- Carbon-carbon bond formation by radical addition-fragmentation reactions of O-tert-alkyl enols and O-cyclopropylcarbinyl enols
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Terminal alkenes of the type H2C=C(OR1)X, in which R1 is a tertiary alkyl or a 1-cyclopropylethyl group and X=Ph, OSiMe2But, OEt or H, undergo radical-chain reactions with organic halides R2Hal to give carbonyl compounds R2CH2C(=O)X.
- Cai, Yudong,Roberts, Brian P.
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Read Online
- Rationalizing the Origin of Solerone (5-Oxo-4-hexanolide): Biomimetic Synthesis and Identification of Key Metabolites in Sherry Wine
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A biomimetic synthesis of solerone (5-oxo-4-hexanolide, 1) using both enzymatic and acid-catalyzed reactions was performed. Starting from L-glutamic acid 5-ethyl ester (2) enzymatic oxidative deamination followed by subsequent decarboxylation of the corresponding 2-oxoglutaric acid 5-ethyl ester (3) led to ethyl 4-oxobutanoate (4). In the presence of pyruvate, 4 served as key substrate for a novel acyloin condensation catalyzed by pyruvate decarboxylase (EC 4.1.1.1) from Saccharomyces cerevisiae. Finally, the resulting ethyl 4-hydroxy-5-oxo-hexanoate (5) was easily converted into solerone (1) in the presence of acid. The acyloin condensation of 3 with acetaldehyde to ethyl 5-hydroxy-4-oxohexanoate (6) revealed an alternative route to solerone (1). Acid-catalyzed lactonization of 6 produced 4-oxo-5-hexanolide (7) as well as 5 and 1 via keto-enol tautomerization. Confirming the relevance of the proposed biogenetic pathway, the solerone precursors 2-6 as well as δ-lactone 7 were identified in sherry by GC/MS analysis for the first time.
- Haering, Dietmar,Schreier, Peter,Herderich, Markus
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- Solvent switched weak interaction of a 4-quinazolinone with a cavitand derivative
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Interaction of 4-quinazolinone with tetrakis (3,5-dicarboxylatophenoxy)-cavitand derivative has been studied in methanol and dimethylformamide media using fluorescence spectroscopy and molecular modeling methods. Results show temperature dependent complex
- Kollár, László,Kunsági-Máté, Sándor,Lemli, Beáta,Nagymihály, Zoltán
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Read Online
- Synthesis and Characterization of Novel Acyl-Glycine Inhibitors of GlyT2
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It has been demonstrated previously that the endogenous compound N-arachidonyl-glycine inhibits the glycine transporter GlyT2, stimulates glycinergic neurotransmission, and provides analgesia in animal models of neuropathic and inflammatory pain. However, it is a relatively weak inhibitor with an IC50 of 9 μM and is subject to oxidation via cyclooxygenase, limiting its therapeutic value. In this paper we describe the synthesis and testing of a novel series of monounsaturated C18 and C16 acyl-glycine molecules as inhibitors of the glycine transporter GlyT2. We demonstrate that they are up to 28 fold more potent that N-arachidonyl-glycine with no activity at the closely related GlyT1 transporter at concentrations up to 30 μM. This novel class of compounds show considerable promise as a first generation of GlyT2 transport inhibitors.
- Mostyn, Shannon N.,Carland, Jane E.,Shimmon, Susan,Ryan, Renae M.,Rawling, Tristan,Vandenberg, Robert J.
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- SYNTHESIS OF RETROFRACTAMIDE A
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The synthesis of the isobutylamide retrofractamide A is described.Key Word index - Piper retrofractum; Piperaceae; alkaloid; retrofractamide A; synthesis.
- Banerji, Avijit,Bandyopadhyay, Debabrata,Siddhanta, Arup K.
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Read Online
- Binuclear Pd(I)-Pd(I) Catalysis Assisted by Iodide Ligands for Selective Hydroformylation of Alkenes and Alkynes
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Since its discovery in 1938, hydroformylation has been thoroughly investigated and broadly applied in industry (>107 metric ton yearly). However, the ability to precisely control its regioselectivity with well-established Rh- or Co-catalysts has thus far proven elusive, thereby limiting access to many synthetically valuable aldehydes. Pd-catalysts represent an appealing alternative, yet their use remains sparse due to undesired side-processes. Here, we report a highly selective and exceptionally active catalyst system that is driven by a novel activation strategy and features a unique Pd(I)-Pd(I) mechanism, involving an iodide-assisted binuclear step to release the product. This method enables β-selective hydroformylation of a large range of alkenes and alkynes, including sensitive starting materials. Its utility is demonstrated in the synthesis of antiobesity drug Rimonabant and anti-HIV agent PNU-32945. In a broader context, the new mechanistic understanding enables the development of other carbonylation reactions of high importance to chemical industry.
- Zhang, Yang,Torker, Sebastian,Sigrist, Michel,Bregovi?, Nikola,Dydio, Pawe?
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supporting information
p. 18251 - 18265
(2020/11/02)
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- PROTEIN KINASE C AGONISTS
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The present disclosure relates generally to certain diacylglycerol lactone compounds, pharmaceutical compositions comprising said compounds, and methods of making and using said compounds and pharmaceutical compositions. The compounds and compositions dis
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Paragraph 0337
(2020/09/12)
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- Synthetic method of aminothiazole compounds
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The invention provides a synthetic method of aminothiazole compounds, and belongs to the technical field of medicine synthesis. The synthetic method comprises the following steps: step f, reacting a compound with a structure as shown in a formula (VI) with selenium dioxide to obtain a compound with a structure as shown in a formula (VII) and the like. The synthetic method of the aminothiazole compound is mainly used for synthesizing the aminothiazole compound, is easy to operate, simple in post-treatment, mild in reaction condition and high in final product yield.
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Paragraph 0085; 0090-0093
(2020/09/09)
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- Phosphine-Catalyzed (4+1) Annulation: Rearrangement of Allenylic Carbamates to 3-Pyrrolines through Phosphonium Diene Intermediates
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We have developed a phosphine-catalyzed (4+1) annulative rearrangement for the preparation of 3-pyrrolines from allenylic carbamates via phosphonium diene intermediates. We employed this methodology to synthesize an array of 1,3-disubstituted- and 1,2,3-t
- Blank, Brian R.,Andrews, Ian P.,Kwon, Ohyun
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p. 4352 - 4372
(2020/08/05)
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- SUBSTITUTED HETEROARYL COMPOUNDS AND METHODS OF USE
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The present invention provides novel heteroaryl compounds, pharmaceutical acceptable salts and formulations thereof. They are useful in preventing, managing, treating or lessening the severity of a protein kinase-mediated disease. The invention also provides pharmaceutically acceptable compositions comprising such compounds and methods of using the compositions in the treatment of protein kinase-mediated disease.
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Paragraph 000523
(2019/06/05)
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- Substituted heteroaryl compounds and compositions and uses thereof (by machine translation)
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The invention discloses substituted heteroaryl compounds and compositions thereof and their use. The compounds of formula (I) compound or type shown in (I) a compound represented by stereo isomers, tautomers, nitrogen oxide, solvate, metabolite, pharmaceutically acceptable salt or its prodrug. The invention also provides a pharmaceutical composition, the compounds and pharmaceutical compositions can be regulated protein kinase, particularly Aurora kinase and JAK kinase activity, for the prevention, treatment, treatment and reduce protein kinase, in particular JAK kinase activity mediated diseases or disorders. (by machine translation)
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Paragraph 1273; 1275; 1276; 1277
(2019/06/07)
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- Chemo- and Regioselective Organo-Photoredox Catalyzed Hydroformylation of Styrenes via a Radical Pathway
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An unprecedented, chemo- and regioselective, organo-photoredox catalyzed hydroformylation reaction of aryl olefins with diethoxyacetic acid as the formylation reagent is described. In contrast to traditional transition metal promoted ionic hydroformylation reactions, the new process follows a unique photoredox promoted, free radical pathway. In this process, a formyl radical equivalent, produced from diethoxacetic acid through a dye (4CzIPN) photocatalyzed, sequential oxidation-decarboxylation route, regio- and chemoselectively adds to a styrene substrate. Importantly, under the optimized reaction conditions the benzylic radical formed in this manner is reduced by SET from the anion radical of 4CzIPN to generate a benzylic anion. Finally, protonation produces the hydroformylation product. By using the new protocol, aldehydes can be generated regioselectively in up to 90% yield. A broad array of functional groups is tolerated in the process, which takes place under mild, metal-free conditions.
- Huang, He,Yu, Chenguang,Zhang, Yueteng,Zhang, Yongqiang,Mariano, Patrick S.,Wang, Wei
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supporting information
p. 9799 - 9802
(2017/08/02)
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- Selective hydroformylation of alkyl acrylates using [2,2′-bis(dipyrrolylphosphinooxy)-1,1′-(±)-binaphthyl]/Rh catalyst: reversal of regioselectivity
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The rhodium-catalyzed hydroformylation of alkyl acrylates with different P-N diphosphine ligands is investigated here. Under mild conditions (syngas pressure: 2 MPa, 20 °C), 2,2′-bis(dipyrrolylphosphinooxy)-1,1′-(±)-binaphthyl (L1) rhodium catalyst could give good conversion of ethyl acrylate (82.9%) in 12 h and exclusive branched aldehyde selectivity of >99.0%. More importantly, on elevating the temperature to 90 °C, this Rh system could preferentially afford the linear aldehyde with 96.1% regioselectivity, and the TOF could reach up to 9000 h?1. Deuterioformylation was conducted to explore the mechanism of regioselectivity reversal, and the results established that the reversible rhodium hydride addition to form the Rh-alkyl species might play a vital role in this reversal. The β-hydride elimination of branched Rh-alkyl species was comparatively stronger than that of linear ones under increased temperature, probably because L1 could cause comparatively larger steric repulsion in branched Rh-alkyl species under high temperature, due to its bulky and rigid binaphthyl backbone characteristics. In turn, the linear Rh-alkyl species progress to linear aldehyde was facilitated.
- Shu, Xiao,Liang, Haoran,Wu, Qianhui,Zhou, Fanding,Zheng, Xueli,Fu, Haiyan,Xu, Bin,Li, Ruixiang,Zhang, Chunchun,Chen, Hua
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p. 14816 - 14823
(2017/03/16)
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- HETEROCYCLIC MODULATORS OF LIPID SYNTHESIS AND COMBINATIONS THEREOF
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Heterocyclic modulators of lipid synthesis are provided as well as pharmaceutically acceptable salts thereof; pharmaceutical compositions comprising such compounds; and methods of treating conditions characterized by disregulation of a fatty acid synthase pathway by the administration of such compounds and combinations of such compounds and other therapeutic agents.
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Page/Page column 268
(2015/07/07)
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- Synthetic strategies for the synthesis and transformation of substituted pyrrolinones as advanced intermediates for rhazinilam analogues
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The biaryl core structure of rhazinilam with its fixed dihedral angle is a pivotal element for its unique in vitro cytotoxic activity. Most of the related natural products are oxidized versions of rhazinilam. Replacing the sensitive pyrrole ring by a pyrrolinone ring is the basis of our initial strategy towards rhazinilam analogues. With this goal, variants of the sequence crossed Mukaiyama aldol reaction followed by the Staudinger reaction were studied. Reacting a suitably substituted acetophenone with O-methyl O-trimethylsilyl ketene acetal gave pyrrolinones 8a and 8b in good to excellent yields. These intermediates could be transformed in four high-yielding steps into the pyrrolic precursors 7a-c containing all the atoms necessary for the construction of rings A, B, and C of rhazinilam. Our studies illustrate a lack of stability of these intermediates. Alternative synthetic approaches towards this central biaryl core structure are described.
- Kholod, Inga,Vallat, Olivier,Buciumas, Ana-Maria,Neels, Antonia,Neier, Reinhard
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supporting information
p. 7865 - 7877
(2015/03/04)
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- DIPEPTIDE AND TRIPEPTIDE EPOXY KETONE PROTEASE INHIBITORS
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Provided herein are dipeptide and tripeptide epoxy ketone protease inhibitors, methods of their preparation, related pharmaceutical compositions, and methods of using the same. For example, provided herein are compounds of Formula (X): and pharmaceutically acceptable salts and compositions including the same. The compounds and compositions provided herein may be used, for example, in the treatment of proliferative diseases including cancer and autoimmune diseases.
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Paragraph 00354; 00355
(2014/10/04)
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- Regioselective ring opening and isomerization reactions of 3,4-epoxyesters catalyzed by boron trifluoride
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Efficient ring opening of 3,4-epoxyesters with alcohols to produce 4-alkoxy-3-hydroxyesters and their isomerization into 4-ketoesters using boron trifluoride as the catalyst are presented. Both transformations are simple and efficient methods for the synthesis of the above named synthetically useful compounds.
- Izquierdo, Javier,Rodriguez, Santiago,Gonzalez, Florenci V.
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supporting information; experimental part
p. 3856 - 3859
(2011/09/19)
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- NAPHTHYLACETIC ACIDS
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The invention is concerned with the compounds of formula (I) and pharmaceutically acceptable salts and esters thereof, wherein X, Q, and R1-R6 are defined in the detailed description and claims. In addition, the present invention relates to methods of manufacturing and using the compounds of formula (I) as well as pharmaceutical compositions containing such compounds. The compounds of formula (I) are antagonists or partial agonists at the CRTH2 receptor and may be useful in treating diseases and disorders associated with that receptor such as asthma.
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Page/Page column 68
(2010/06/15)
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- TRIAZINE DERIVATIVES AND THEIR THERAPEUTICAL APPLICATIONS
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The present invention comprises inter alia compounds as shown in formula (I) or a pharmaceutically acceptable salt thereof.
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Page/Page column 118
(2010/12/29)
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- Synthetic studies toward pectenotoxin 2. Part II. Synthesis of the CDE and CDEF ring systems
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(Chemical Equation Presented) A convergent synthesis of the CDE and CDEF ring systems of pectenotoxin-2 from C and F ring precursors is described.
- Helmboldt, Hannes,Aho, Jatta E.,Pinko, Petri M.
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supporting information; experimental part
p. 4183 - 4185
(2009/05/30)
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- A general and efficient reduction of acyl chlorides to aldehydes by Sm(0)/Bu3P
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A facile and efficient reduction of aromatic and aliphatic acyl chlorides to their corresponding aldehydes in the presence of Sm(0)/Bu3P has been developed with broad scope. This method prevents over reduction of products, that is, the over-reduction of aldehydes to alcohols.
- Jia, Xueshun,Liu, Xiaotao,Li, Jian,Zhao, Peichao,Zhang, Yongmin
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p. 971 - 974
(2008/02/04)
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- Catalysis by water-soluble organometallic complexes in water-in-densified fluid microemulsions
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A microemulsion containing water, a densified fluid, a surfactant, and an organometallic catalyst is used to catalyze chemical reactions. The organometallic catalyst preferably has substantial solubility in the water phase of the microemulsion. Separation of reaction products from the microemulsion is facilitated by removal of the densified fluid.
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- Benzoxazepinones and their use as squalene synthase inhibitors
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There is disclosed a compound represented by the formula [I]: wherein R1 is optionally substituted 1-carboxyethyl group, optionally substituted alkyl-sulfonyl group, optionally substituted (carboxy-cycloalkyl)-alkyl group, -X1-X2-Ar-X3-X4-COOH (wherein X1 and X4 are a bond or alkylene group, X2 and X3 are a bond, -O-, -S-, Ar is divalent aromatic group etc.), R2 is alkyl group optionally substituted with alkanoyloxy group and/or hydroxy group, R3 is alkyl group, and W is halogen atom, etc., or a salt thereof. The compound has the cholesterol lowering activity and the triglyceride lowering activity and is useful for preventing and/or treating hyperlipidemia.
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- Hydroformylation with unmodified rhodium catalysts in supercritical carbon dioxide
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The present invention relates to processes for the preparation of oxo products by the hydroformylation of substrates having C═C double bonds using unmodified rhodium catalysts in a reaction mixture essentially consisting of the substrates, the catalyst and carbon dioxide in a supercritical state (scCO2). In particular, the invention relates to such processes for the preparation of products which contain substantial proportions of branched i-oxo products. Further, the invention relates to such processes for the hydroformylation of substrates which do not correspond to the general formula CnH2n. The invention further relates to such processes in which the separation of product and catalyst is effected using the special solvent properties of scCO2.
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(2008/06/13)
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- 2,4-Dithi(oxo)-pyrimidin-5-yl compounds bearing a tricyclic substituent useful as P2 purinoceptor antagonists
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PCT No. PCT/SE98/01240 Sec. 371 Date Sep. 30, 1998 Sec. 102(e) Date Sep. 30, 1998 PCT Filed Jun. 25, 1998 PCT Pub. No. WO99/02501 PCT Pub. Date Jan. 21, 1999The invention relates to new pharmaceutically active compounds which are P2-purinoceptor 7-transmembrane (TM) G-protein coupled receptor antagonists, compositions containing them and processes for their preparation.
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- Enantiospecific Formation of Trans 1,3-Disubstituted Tetrahydro-β-carbolines by the Pictet-Spengler Reaction and Conversion of Cis Diastereomers into Their Trans Counterparts by Scission of the C-1/N-2 Bond
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The factors which effect the stereoselective formation of trans-1-alkyl-2-benzyl-3-(alkoxycarbonyl)-1,2,3,4-tetrahydro-β-carbolines and trans-3-(alkoxycarbonyl)-1-alkyl-2-(diphenylmethyl)-1,2,3,4-tetrahydro-β- carbolines by the Pictet-Spengler cyclization were examined by heating tryptophan derivatives with aldehydes of varied steric bulk under aprotic and acidic conditions, followed by determination of the ratio of cis to trans diastereomers so formed. The presence of a benzyl group at the Nb-nitrogen atom alters the diastereochemical outcome of this condensation to provide 100% trans stereoselectivity when the cyclization is carried out with cyclohexanecarboxaldehyde. Furthermore, when Nb-(diphenylmethyl)tryptophan isopropyl ester was condensed with aldehydes of any size, trans diastereomers are formed with 100% stereoselectively. The trans Nb-substituted diastereomers are thermodynamically more stable than their cis congeners as shown by equilibration experiments in TFA. Conversion of the cis diastereomers into the more stable trans diastereomers is believed to occur under acidic conditions by cleavage of the carbon (C-1)-nitrogen (N-2) bond with complete retention of configuration at the C-3 stereocenter. Evidence from deuterium exchange experiments as well as optical rotations support this model for epimerization. In addition, when cis diastereomer 66a was allowed to stir in CF3COOD, the trans isomer 66b was isolated in 90% yield, while treatment of cis 66a with CF3COOH/NaBH4 provided a mixture of the ring cleaved [scission across C(1)-N(2) bond] product 67 and the trans isomer 66b. Treatment of 66b (control experiment) with NaBH4/CF3COOH under the same conditions returned only starting trans 66b in excellent yield. The Pictet-Spengler reaction of substrates with sufficiently large substituants, followed by treatment with acid, permits the 100% enantiospecific formation of trans-1,3-disubstituted-1,2,3,4-tetrahydro-β-carbolines for alkaloid total synthesis.
- Cox, Eric D.,Hamaker, Linda K.,Li, Jin,Yu, Peng,Czerwinski, Kevin M.,Deng, Li,Bennett, Dennis W.,Cook, James M.,Watson, William H.,Krawiec, Mariusz
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- Aromatic annulation: Two new methods for the synthesis of chiral bicyclic phenols
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Two selective and mild aromatic annulation procedures are described for the synthesis of chiral substituted tetrahydronaphthalene derivatives from (-)-menthone and (+)-dihydrocarvone.
- Corey,Palani, Anandan
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p. 2397 - 2400
(2007/10/03)
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- Transformation of acid chlorides into aldehydes by reduction of in-situ formed acyltributylphosphonium ions with zinc-copper couple or zinc
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Transformation of acid chlorides into the corresponding aldehydes without over-reduction to alcohols was effectively achieved by the reduction of acyltributylphosphonium ions, formed in-situ from the chlorides and tributylphosphine in CH3CN, with Zn-Cu couple or Zn in the presence of CH3SO3H under an N2 atmosphere.
- Maeda, Hatsuo,Maki, Toshihide,Ohmori, Hidenobu
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p. 2247 - 2250
(2007/10/02)
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- Phyllanthoside-Phyllanthostatin Synthetic Studies. 7. Total Synthesis of (+)-Phyllanthocin and (+)-Phyllanthocindiol
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A stereochemically linear total synthesis of (+)-phyllanthocin (5a), the aglycon methyl ester of the antineoplastic glycoside (+)-phyllanthoside (1), is described. The synthesis proceeds in 23 steps (4.5% overall yield) and affords (+)-phyllanthocin in high enantiomeric purity. The central features of the strategy include: (a) construction of aldehyde 8 via a stereoselective, intramolecular ene reaction; (b) elaboration of the spiroketal unit by a two-step tactic involving addition of a functionalized dihydropyran anion (i.e., 9) to 8, followed by a highly stereoselective spiroketalization; and (c) chemo- and stereoselective methylenation of the C(7) carbonyl group. In addition, a second-generation approach is presented, wherein an augmented spiroketalization maneuver not only establishes the C(8) spirocenter but also permits the regio- and stereocontrolled introduction of the C(11) methyl group. The latter sequence furnishes (+)-phyllanthocin in 21 steps (5.6% overall yield). Finally, the advanced phyllanthocin intermediate (+)-49 is converted in five steps (42% overall yield) to (+)-phyllanthocindiol (5b), the aglycon of phyllanthostatin 3.
- Smith III, Amos B.,Fukui, Mineo,Vaccaro, Henry A.,Empfield, James R.
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p. 2071 - 2092
(2007/10/02)
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- STEREOKONVERGENT SYNTHESIS OF A POTENT MOSQUITO LARVICIDE : (2E,4E,8E,10Z)-N-(2-METHYL PROPYL)-2,4,8,10-DODECATETRAENEAMIDE
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First total synthesis of (2E,4E,8E,10Z)-N-(2-methyl propyl)-2,4,8,10-dodecatetraene amide (1), by the condensation of (4E,6Z)-octadienyl phenyl sulfone (2) and ethyl-4-oxobutanoate (3) followed by double elimination reaction, which involves easily accessible reagents and simple transformations is described.
- Sharma, G. V. M.,Shekharam, T.,Upender, V.
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p. 5665 - 5672
(2007/10/02)
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- CARBOPALLADATION DES ALKYLIDENECYCLOPROPANES-II; CAPTURE INTERMOLECULAIRE DE L'ORGANOPALLADIQUE INTERMEDIAIRE
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The reaction of an alkylidenecyclopropane of type 1 bearing an internal nucleophile (β-diester, β-keto-ester, β-sulfonyl-ester, amine) with iodobenzene in the presence of catalytic amounts of a palladium (0) complex leads to cyclic compounds 3 and (or) 4
- Fournet, Guy,Balme, Genevieve,Barieux, Jean Jacques,Gore, Jacques
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p. 5821 - 5832
(2007/10/02)
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- Synthesis of Δ3-1-Methylene-1-carbacephems
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The total synthesis of (+/-)-1-methylene-2,2-dimethyl-7-amino-1-carbacephem-4-carboxylic acid (1) is described.The reaction scheme was essentially that described by Christensen et al. for the synthesis of (+/-)-1-carbacephems.In vitro antibacterial activities of the 7-phenoxyacetyl and 7-D-α-phenylglycyl derivatives of 1 were compared with those of 7-(phenoxyacetamido)desacetoxycephalosporanic acid and cefalexin.Derivatives of 1 were 2-4 times less active against most of the sensitive organisms than the corresponding 7-aminodesacetoxycephalosporanic acid analogues.The activity of the 7-D-α-phenylglycyl derivative of 1 however was about 20 times lower than that of cefalexin when measured against Staphylococcus aureus ATCC 6538P.
- Herdewijn, Piet,Claes, Paul J.,Vanderhaeghe, Hubert
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p. 661 - 664
(2007/10/02)
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- The "Normalizing Factor" for the Tomato Mutant chloronerva. XXIII. Deaminonicotianamine and 2-Decarboxynicotianamine
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Deaminonicotianamine (8) and 2-decarboxynicotianamine (11) were synthesized by stepwise reductive alkylation of (S)-2-ethoxycarbonylazetidine (3) or azetidine (9) with ethyl (S)-4-oxo-2-(trifluoroacetylamino)butanoate (4) and ethyl 4-oxobutanoate (7), respectively.The amino acids 8 or 11 as well as the intermediates, (2S,αS)-α-amino-2-carboxy-1-azetidinebutanoic acid (6) and (S)-α-amino-1-azetidinebutanoic acid (10) did not show biological activity with regard to chlorophyll synthesis in chlorotic leaflets of the tomato mutant chloronerva.The compound 11 promoted the normally inhibited root growth of the mutant.
- Ripperger, H.
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p. 719 - 723
(2007/10/02)
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- STANNYL ESTER CYCLIZATIONS
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Alpha halo stannyl esters react with alkenes to afford lactones.The reaction is catalyzed by AIBN.The reaction proceeds best with electron rich alkenes.The mechanistic aspects of this novel reaction are discussed.This reaction can also be conducted intramolecularly to produce bicyclic lactones.An approach to the lignan system is presented.
- Kraus, George A.,Landgrebe, Kevin
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p. 4039 - 4046
(2007/10/02)
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- Importance of allylic interactions and stereoelectronic effects in dictating the steric course of the reaction of iminium ions with nucleophiles. An efficient total synthesis of (±) gephyrotoxin
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A stereocontrolled total synthesis of (±)-gephyrotoxin in 15 steps and 6.5% overall yield from benzyl trans-1,3-butadiene-1-carbamate is described. A key step is reduction of octahydroquinoline 27 from the more hindered concave α face to provide decahydroquinoline 28. This unusual transformation results from the interplay of allylic (A1,2) steric interactions and stereoelectronic effects.
- Overman,Lesuisse,Hashimoto
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p. 5373 - 5379
(2007/10/02)
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