- Synthesis of (+)-goniopypyrone and (+)-goniotriol using Pd-catalyzed carbonylation
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Syntheses of (+)-goniopypyrone and (+)-goniotriol isolated from Goniothalamus giganteus were achieved. The key steps involve Pd-catalyzed carbonylation for lactone ring formation and diastereoselective reduction of ynone using the (R)-CBS catalyst and borane dimethyl sulfide complex.
- Miyazawa, Yuki,Sugimoto, Makoto,Tanaka-Oda, Ayumi,Makabe, Hidefumi
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- Stereocontrolled synthesis of four isomeric linoleate triols of relevance to skin barrier formation and function
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Linoleate triol esters are intermediates along the pathway of formation of the mammalian skin permeability barrier. In connection with the study of their involvement in barrier formation we required access to isomerically pure and defined samples of four linoleate triol esters. A common synthetic strategy was developed starting from isomeric alkynols derived from D-tartaric acid and 2-deoxy-D-ribose.
- Davis, Robert W.,Allweil, Alexander,Tian, Jianhua,Brash, Alan R.,Sulikowski, Gary A.
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supporting information
p. 4571 - 4573
(2018/11/23)
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- Chiroptical properties of 2,2’-bioxirane
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The two enantiomers of 2,2′-bioxirane were synthesized, and their chiroptical properties were thoroughly investigated in various solvents by polarimetry, vibrational circular dichroism (VCD), and Raman optical activity (ROA). Density functional theory (DFT) calculations at the B3LYP/aug-cc-pVTZ level revealed the presence of three conformers (G+, G?, and cis) with Gibbs populations of 51, 44, and 5% for the isolated molecule, respectively. The population ratios of the two main conformers were modified for solvents exhibiting higher dielectric constants (G? form decreases whereas G+ form increases). The behavior of the specific optical rotation values with the different solvents was correctly reproduced by time-dependent DFT calculations using the polarizable continuum model (PCM), except for the benzene for which explicit solvent model should be necessary. Finally, VCD and ROA spectra were perfectly reproduced by the DFT/PCM calculations for the Boltzmann-averaged G+ and G? conformers.
- Daugey,De Rycke,Brotin,Buffeteau
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supporting information
p. 342 - 350
(2018/01/15)
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- Convergent Synthesis of the Dihydropyran Core Containing the C1-C15 Subunit of Sorangicin A Employing Gold(I)-Catalyzed Cyclization of an Allenic Alcohol
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A convergent route to the C1-C15 subunit of sorangicin A is disclosed. The key steps include carbon-carbon bond formation using an α-chloro sulfide, regioselective hydrozirconation of an internal alkyne for the preparation of a trisubstituted iodoalkene, allene formation using the Myers-Movassaghi protocol, stereoselective reduction of allylic and propargylic ketones using Noyori's catalyst, and gold(I)-catalyzed cyclization of a β-hydroxy allene to construct the dihydropyran ring.
- Raghavan, Sadagopan,Nyalata, Satyanarayana
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supporting information
p. 10698 - 10706
(2016/11/29)
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- Design of Highly Stable Iminophosphoranes as Recyclable Organocatalysts: Application to Asymmetric Chlorinations of Oxindoles
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A new family of tartaric acid derived chiral iminophosphoranes has been developed as highly effective organocatalysts in the asymmetric chlorinations of 3-substituted oxindoles with a high level of enantioselectivity. Importantly, these catalysts are air- and moisture-stable. Recovery of the catalyst after simple chromatographic separation for reuse in the model reaction was achieved; the catalyst can be recycled six times without loss of any enantioselectivity. Several advantages of this catalytic process are high conversion after a very short reaction time at ambient temperature, low catalytic loading, and scale-up to multigram quantities with an excellent enantiomeric excess value of >99%, which meets the enantiomeric purity required for pharmaceutical purposes.
- Gao, Xing,Han, Jianwei,Wang, Limin
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supporting information
p. 4596 - 4599
(2015/09/28)
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- Versicolactones A and B: Total synthesis and structure revision
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To further determine absolute configurations of versicolactones A and B, total synthesis of versicolactones A and B and their six stereoisomers were reported in this Letter. The 1H and 13C NMR spectra of the synthetic erythro-stereoisomers matched perfectly with those of the natural products. Combined with the comparison of the specific rotations, the absolute configuration of versicolactones A and B were revised as (4Z,6R,7S)- and (4E,6R,7S)- from the corresponding (4Z,6R,7R)- and (4E,6R,7R)-6,7-dihydroxyocta- 2,4-dien-4-lactone, respectively.
- Wang, Liping,Zhu, Weiming
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supporting information
p. 6729 - 6731
(2013/11/19)
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- A Total synthesis of aliskiren starting from D-Tartrate diester
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A formal total synthesis of aliskiren was accomplished. A key in our synthesis was to use the symmetric ciscisoid-Cis-Bis-Lactone 3' as a precursor, which was prepared from D-tartrate diester. Appending the end groups and functional group transformations completed the synthesis.
- Kim, Ji Hei,Ko, Soo Y.
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p. 3777 - 3781
(2014/01/17)
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- A C2-symmetric pool based flexible strategy: An enantioconvergent synthesis of (+)-valiolamine and (+)-valienamine
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A new enantioconvergent strategy directed toward the synthesis of glucosidase inhibitors was developed by using a C2-symmetric element within the chiral pool and by applying an iodine-promoted cyclization of an unsaturated carbonimidothioate for the regio- and diastereocontrolled installation of amino and hydroxy units. Not only does this simple flexible strategy provide a convergent concise approach to (+)-valiolamine (1), but it can also be readily adopted for the synthesis of (+)-valienamine (2). Commercially available and cheap C2-symmetric D-tartaric acid served as the chiral building block. Copyright
- Lo, Hong-Jay,Chen, Cheng-Yih,Zheng, Wei-Lin,Yeh, Shang-Ming,Yan, Tu-Hsin
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experimental part
p. 2780 - 2785
(2012/07/14)
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- A C2-symmetric pool based synthesis of the furanoside of hygromycin A
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The readily available and inexpensive D-tartaric acid serves as the chiral building block for synthesis of the furanoside of hygromycin A. Key to our successes in the asymmetric synthesis of the furanose segment was the melding of several key reactions, such as the successful application of the monosilylation of C2-symmetric diol, diastereocontrolled di(2-propenyl)zinc addition to the aldehyde, and TMSCl-MeOH promoted desilylation, acetal-cleavage, and intramolecular esterification in one-step.
- Lo, Hong-Jay,Chang, Yuan-Kang,Lin, Feng-Yi,Yan, Tu-Hsin
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p. 687 - 695
(2013/08/15)
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- Synthesis of novel mucic acid 1,4-lactone methyl ester 3-O-ferulate related to an extractive component isolated from the peels of Citrus sudachi
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Synthesis of a new type of mucic acid 1,4-lactone methyl ester 3-O-ferulate related to an extractive component isolated from Citrus sudachi, and its diastereomer has been achieved by employing stereodivergent dihydroxylation as a key step. The structures of the final products are fully characterized by spectroscopic methods and compared with that of the natural product.
- Sengoku, Tetsuya,Murata, Yusuke,Mitamura, Hiromi,Takahashi, Masaki,Yoda, Hidemi
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p. 435 - 437
(2012/02/03)
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- Chiral pool based efficient synthesis of the aminocyclitol core and furanoside of (-)- hygromycin A: Formal total synthesis of (-)-hygromycin A
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A chiral pool based synthetic strategy that leads from the readily available and inexpensive C2-symmetric tartaric acids to the chiral O-isopropylidenebenzooxazolei- a convenient precursor to the aminocyclitol core of hygromycin A as well as the chiral γ-disilyloxybutyrolactone-a pivotal intermediate to approach to the furanoside of hygromycin A.
- Lo, Hong-Jay,Chang, Yuan-Kang,Yan, Tu-Hsin
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supporting information
p. 5896 - 5899
(2013/02/23)
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- Synthesis of an acyclic C1-C11 fragment of peloruside B
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The synthesis of a C1 reduced form of the C1-C11 fragment of peloruside B has been achieved in 15 synthetic steps. The strategy involved the use of D-tartaric acid to set the absolute stereochemistry and a 1,5-anti Mukiayama aldol reaction. Analog synthesis of C8-C11 is also reported, which enables changes at the C10 position of peloruside B to be made. The synthesis of the fragment concludes with C1 in the protected alcohol state rather than the natural ester. The synthesis of a C1 reduced form of the C1-C11 fragment of peloruside B was achieved in 15 synthetic steps. D-Tartaric acid was used to set the absolute stereochemistry, and a 1,5-anti Mukiayama aldolreaction was a key step. The methodology allows the framework to be synthesized in a remarkably efficient manner and enables changes to be made at the C10 position.
- Zang, Qin,Gulab, Shivali,Stocker, Bridget L.,Baars, Sylvia,Hoberg, John O.
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scheme or table
p. 4465 - 4471
(2011/10/02)
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- Synthesis of glycocinnasperimicin D
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The first total synthesis of amino sugar antibiotic glycocinnasperimicin D (1) has been achieved by a convergent, three-component coupling strategy. The key steps involve the Heck-Mizoroki reaction by using the iodophenyl glycoside 50 and acryl amide 32 to furnish the right core structure of 1, and the construction of the urea glycoside employing the reaction of glycosyl isocyanate 8 with amino sugar 9. Glycosyl isocyanate 8 was prepared by the oxidation of isonitrile 10, which displayed excellent reactivity in the coupling event. Synthetic roadblocks, encountered during this synthetic effort, have led to the development of the α-selective, Lewis acid catalyzed phenyl glycosylation process with 2-amino-hexopyranose and a procedure for acetonide deprotection without affecting the silyl ethers.
- Nishiyama, Taihei,Kusumoto, Yoshifumi,Okumura, Ken,Hara, Kanako,Kusaba, Shohei,Hirata, Keiko,Kamiya, Yukihiro,Isobe, Minoru,Nakano, Keiji,Kotsuki, Hiyoshizo,Ichikawa, Yoshiyasu
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scheme or table
p. 600 - 610
(2010/05/02)
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- NEUROLOGICALLY-ACTIVE COMPOUNDS
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The invention provides a compound of the formula (I): wherein R is methyl, ethyl, propyl, isopropyl, butyl, pentyl, neo-pentyl or cyclohexyl, or a salt or solvate thereof. These compounds are selective GABAC receptor antagonists. The invention also provides pharmaceutical compositions comprising a compound of formula (I) or a pharmaceutically acceptable salt or solvate thereof. The invention also provides methods of enhancing the cognitive activity of an animal and methods of stimulating memory capacity in an animal, comprising the step of administering to the animal an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt or solvate thereof.
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Page/Page column 11-12
(2008/06/13)
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- Synthesis of novel chiral macrocyclic polyamides derived from L-/D-tartaric acid
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A convenient and efficient synthesis of chiral macrocyclic polyamides derived from L-/D-tartaric acid is reported. These chiral compounds could not only be used for chiral recognition, but also provide a feasible way to synthesize chiral macrocycles. Copyright Taylor & Francis, Inc.
- Li, Baohua,Yang, Xuemei,Yang, Kai,Fu, Enqin
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p. 2603 - 2608
(2007/10/03)
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- Total synthesis of (-)-microcarpalide, a novel microfilament disrupting metabolite
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The stereoselective total synthesis of (-)-microcarpalide, a recently discovered 10-membered lactone of fungal origin displaying a remarkable disrupting action on actin microfilaments, was accomplished by using ring-closing metathesis (RCM) as the key step for the formation of the medium-sized ring. The diene ester required for the macrocyclization reaction was assembled via DCC-mediated esterification of two suitable partners, each bearing a terminal alkene group. The alcohol fragment was synthesized from n-bromohexane through a seven-step sequence entailing two consecutive stereoselective homologations of chiral boronic esters as strategic transformations for the sequential insertion of the two stereocentres with the final S absolute configuration, using (+)-pinanediol as the chiral director; final elaboration to the desired C11 framework envisaged treatment with an allyl Grignard reagent and oxidative cleavage of the boronic scaffold. In contrast, the acidic fragment was prepared in ten steps from D-tartaric acid, whose C4 backbone was elongated to the required C7 skeleton by means of two distinct Swern-Wittig oxidation-homologation sequences.
- Davoli, Paolo,Spaggiari, Alberto,Castagnetti, Luca,Prati, Fabio
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- Synthesis of a chiral aziridine derivative as a versatile intermediate for HIV protease inhibitors.
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[reaction: see text] Chiral aziridine derivative 1 was prepared from D-tartaric acid. This compound could be utilized as a common intermediate for the synthesis of hydroxyethylamine class HIV protease inhibitors such as saquinavir, amprenavir, or nelfinavir.
- Kim,Bae,So,Yoo,Chang,Lee,Kang
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p. 2349 - 2351
(2007/10/03)
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- A synthesis of the HIV-protease inhibitor nelfinavir from D-tartaric acid
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This letter describes a new synthesis of the HIV-protease inhibitor nelfinavir. The synthesis features a selective opening of a D-tartaric acid-derived cyclic sulfate with nitrogen nucleophiles.
- Albizati, Kim F.,Babu, Srinivasan,Birchler, Angela,Busse, Juliette K.,Fugett, Michelle,Grubbs, Alan,Haddach, Aubrey,Pagan, Miguel,Potts, Barbara,Remarchuk, Travis,Rieger, Dale,Rodriguez, Rick,Shanley, Jim,Szendroi, Robert,Tibbetts, Tony,Whitten, Kathleen,Borer, Bennett C.
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p. 6481 - 6485
(2007/10/03)
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- The effects of different ester and ketal protecting groups on the reactivity and selectivity of tartrate-derived silylketene acetals
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The reaction of tartrate-derived silylketene acetals and benzaldehyde has been investigated and the yields and diastereoselectivities have been found to be dependent upon the nature of the tartrate ester. Utilising the di-to7-butyl tartrate derivatives, high yields were achieved using a variety of aldehyde substrates. The reactions all proceeded with excellent levels of stereoselectivity (== 82:18); the sense of induction being dependent upon the choice of Lewis acid. BF3-OEt2 and TiCl3(OiPr) furnished complementary products in several cases and a model has been proposed to account for this observation.
- Agganval, Varinder K.,Masters, Susannah J.,Adams, Harry,Spey, Sharon E.,Brown, George R.,Foubister, Alan J.
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p. 155 - 162
(2007/10/03)
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