- Access to Anti or Syn 2-Amino-1,3-diol Scaffolds from a Common Decarboxylative Aldol Adduct
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A straightforward synthetic pathway allowing the access to anti or syn 2-amino-1,3-diol scaffolds is presented. The strategy relies on a diastereoselective organocatalyzed decarboxylative aldol reaction of a N-Boc-hemimalonate that is easily formed from commercial N-Boc-diethyl malonate. Although this method has been optimized previously with the N-Bz-hemimalonate analogue, this key step was reinvestigated with the N-Boc derivative to improve the required reaction time, the yield, and the diastereoselectivity. The new conditions enhance this transformation, and quantitative yields and anti/syn ratios up to 96:4 can be obtained. The anti aldol product was easily isolated in pure form and then taken forward as the key precursor in the preparation of both a set of ten N-/O-alkylated anti 2-amino-1,3-diol derivatives and the syn congeners.
- Chaumont, Pauline,Baudoux, Jérome,Maddaluno, Jacques,Rouden, Jacques,Harrison-Marchand, Anne
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p. 8081 - 8091
(2018/07/09)
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- Oxidant controlled regio- and stereodivergent azidohydroxylation of alkenes via I2 catalysis
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A novel, I2 catalyzed regio- and stereodivergent vicinal azidohydroxylation of alkenes leading to 1,2-azidoalcohols in high yields (up to 92%) and excellent dr (up to 98%) has been developed. This unprecedented transformation employs NaN3 and DMF as N- and O-nucleophiles respectively. The role of DMF as the O-source in the reaction has been unequivocally proven by 18O labelling studies.
- Prasad,Reddi,Sudalai
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supporting information
p. 10276 - 10279
(2015/06/25)
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- PPMP as a ceramide catabolism inhibitor for cancer treatment
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The present invention relates to a method of treating a hyperproliferative disorder comprising administering a ceramide generating retinoid comprising a retinoic acid derivative or a pharmaceutically acceptable salt thereof, and D-threo-PPMP as a ceramide degradation inhibitor or a pharmaceutically acceptable salt thereof, wherein the hyperproliferative disorder is a tumor; and wherein the ceramide generating retinoid is administered in an amount effective to produce necrosis, apoptosis or both in the tumor, and the ceramide degradation inhibitor is administered in an amount effective to increase the necrosis, apoptosis or both in the tumor over that expected to be produced by the sum of that produced by the ceramide generating retinoid and the ceramide degradation inhibitor when administered separately.
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Page/Page column 5; sheet 6
(2010/02/11)
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- Amino acid analogs as CCK antagonists
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Novel unnatural dipeptoids useful as agents in the treatment of obesity, hypersecretion of gastric acid in the gut, gastrin-dependent tumors, or as antipsychotics are disclosed. Further, the compounds are antianxiety agents and antiulcer agents. The compounds are agents useful for preventing the response to withdrawal from chronic treatment or use of nicotine, diazepam, alcohol, cocaine, caffeine, and opioids. The compounds are also useful in treating and/or preventing panic attacks. Also disclosed are pharmaceutical compositions and methods of treatment using the dipeptoids as well as processes for preparing them and novel intermediates useful in their preparation. An additional feature of the invention is the use of the subject compounds to prepare diagnostic compositions.
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- Stereo-selective synthesis of 2-aryl-propionic acids of high optical purity by using chiral oxazolines
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The present invention relates to a stereospecific chemical synthesis of optically pure enantiomers of 2-aryl-alkanoic acids, especially those of the biologically active (S)-aryl-propionic acids, in good chemical yields, useful for preparing large quantities thereof, and having a high optical purity.
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- STEREOSELECTIVE SYNTHESIS OF (+/-)-threo-2-AMINO-1-(4-NITROPHENYL)-1,3-PROPANEDIOL
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Addition of hypobromic acid to styrene afforded styrene bromohydrin (I) which was dehydrated to ω-bromostyrene (II).Prince reaction of II with aqueous formaldehyde gave 5-bromo-4-phenyl-1,3-dioxane (III).The bromine atom in III was replaced with amino group by treatment with methanolic ammonia at 150 deg C and 6 - 8 MPa and the obtained threo-5-amino-4-phenyl-1,3-dioxane (IVa) was hydrolyzed to give (+/-)-threo-2-amino-1-phenyl-1,3-propanediol (V).Suitably chosen method of nitration converted the free base IVa or its N-acetyl derivative IVb into 5-amino-4-(4-nitrophe nyl)-1,3-dioxane (VIa) or its N-acetyl derivative VIb which without isolation were hydrolyzed to threo-2-amino-1-(4-nitrophenyl)-1,3-propanediol (VII), isolated as hydrochloride.The liberated base was resolved into enantiomers and dichloroacetylated in the known manner to give D-(-)-threo-2-dichloroacetylamino-1-(4-nitrophenyl)-1,3-propanediol (chloramphenicol).
- Cervinka, Otakar,Dudek, Vaclav,Fabryova, Anna,Kolar, Jiri,Lukac, Juraj,et al.
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p. 2748 - 2752
(2007/10/02)
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- PHOTOLABILE p-METHOXYPHENACYLOXYCARBONYL GROUP FOR THE PROTECTION OF AMINES
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P-Methoxyphenacyloxycarbonyl (Phenoc) is a new photolabile protective group for amines.Various phenacyl urethanes, i.e.Phenoc protected amines, have been prepared.An application of the group in peptide synthesis is reported.
- Church, George,Ferland, Jean-Marie,Gauthier, Jean
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p. 1901 - 1904
(2007/10/02)
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- Resolution of Racemic Amines with 2-Methyl-2-phenylbutanedioic Acid
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Five racemic amines were resolved in high chemical and optical yields using (S)-(+)-2-methyl-2-phenylbutanedioic acid as resolving reagent.The reagent can be recovered quantitatively and without any change in its optical purity. (R)-(-)-2-Methyl-2-phenylbutanedioic acid was also obtained.
- Gharpure, Milind M.,Rao, A. S.
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p. 410 - 411
(2007/10/02)
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- Reversed-phase liquid chromatographic separation of enantiomeric and diastereomeric bases related to chloramphenicol and thiamphenicol.
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The important antimicrobial agents chloramphenicol and thiamphenicol are N-acylated amines whose chemical structures include two chiral centers. Each drug is the single enantiomer of R,R configuration. The N-deacylated bases of the drugs are important intermediates in their synthesis and optical resolution. In this report, reversed-phase HPLC methods are described for the separation of enantiomeric and diastereomeric bases of the two drugs and of two closely related bases used in some syntheses of the drugs. The stereoisomeric bases were derivatized with a homochiral isothiocyanate and the resulting diastereomeric thioureas were separated on C18 columns with methanol:water mixtures as mobile phases and detection at 254 nm. The four stereoisomeric bases of chloramphenicol and those of its unnitrated analogue were thus separable after derivatization with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate. This reagent also allowed the separation of the D-threo isomer of the p-mercaptomethyl analogue of thiamphenicol base from its stereoisomers. The stereoisomers of thiamphenicol base were similarly separated with (R)-alpha-methylbenzyl isothiocyanate as the derivatizing agent. The diastereomers of chloramphenicol base and of thiamphenicol base were chromatographically separable after derivatization with the nonchiral reagent benzyl isothiocyanate. The procedures developed may be useful in the determination of the stereoisomeric composition of the drugs in research and in quality control, and may be applicable to other similar agents whose chemistry and pharmacology are receiving considerable attention.
- Gal,Meyer-Lehnert
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p. 1062 - 1065
(2007/10/02)
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- Note on a Simple Synthesis of (+/-)-threo-2-Amino-1-phenyl-1,3-propanediole
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A synthesis of the title compound starting from methyl trans-5-phenyl-2-oxazoline-4-carboxylate (3) is described.
- Schoellkopf, Ulrich,Scheunemann, Karl-Heinz
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p. 1348 - 1349
(2007/10/02)
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