Enantioselective synthesis of (S)- and (R)-α-methylserines: application to the synthesis of (S)- and (R)-N-Boc-N,O-isopropylidene-α-methylserinals
摘要:
This report describes the synthesis of enantiomerically pure (S)- and (R)-alpha -methylserines on a multigram scale, starting from the Weinreb amide of 2-methyl-2-propenoic acid and using a stereodivergent synthetic route that involves a Sharpless asymmetric dihydroxylation reaction. As a synthetic application of these quaternary alpha -amino acids, they were used as starting materials in the synthesis of the well-known valuable homochiral (S)- and (R)-N-Boc-N,O-isopropylidene-alpha -methylserinal building blocks. (C) 2001 Elsevier Science Ltd. All rights reserved.
An alternative approach to (S)- and (R)-2-methylglycidol O-benzyl ether derivatives
作者:Alberto Avenoza、Carlos Cativiela、Jesús M. Peregrina、David Sucunza、Marı́a M. Zurbano
DOI:10.1016/s0957-4166(01)00230-0
日期:2001.6
This report describes the gram scale synthesis of (S)- and (R)-2,2,4-trimethyl-4-(hydroxymethyl)-1,3-dioxolanes using the Sharpless asymmetric dihydroxylation (AD) of the Weinreb amide of 2-methyl-2-propenoic acid. The 2-methylglycerol acetonides resultant from protection of the AD products were used as starting materials in the synthesis of O-benzyl ethers of the valuable C4-chiral building blocks (S)- and (X)-2-methylglycidol. (C) 2001 Elsevier Science Ltd. All rights reserved.
Preparation of 2(R) and 2(S) methyl-2-methylglycerates
作者:Juan B. Rodríguez、Sanford P. Markey、Herman Ziffer
DOI:10.1016/s0957-4166(00)86020-6
日期:1993.1
Optically pure samples of both enantiomers of methyl 2,3-dihydroxy-2-methylpropanoate were prepared by a chromatographic separation of their (-)-menthyl esters followed by hydrolysis and methylation. Their absolute stereochemistries were established by conversion into their 3-0-acetyl derivatives, compounds of established configuration. NMR and CG-MS methods of determining the optical purities of the diols are described.
Asymmetric synthesis of 2-alkyl-2,3-dihydroxypropionates from glycerol
作者:Kuang-Fu Yen、Biing-Jiun Uang
DOI:10.1016/s0957-4166(00)80504-2
日期:1992.6
The preparation of optically active 2-substituted 2,3-dihydroxypropionates from glycerol is described.
Enantioselective Synthesis of α-Methyl-<scp>d</scp>-cysteine and Lanthionine Building Blocks via α-Methyl-<scp>d</scp>-serine-β-lactone
作者:Nicole D. Smith、Murray Goodman
DOI:10.1021/ol034025p
日期:2003.4.1
[GRAPHICS]We report here the enantioselective synthesis of Boc-alpha-methyl-D-cysteine(PMB)-OH and lanthionine building blocks through the regloselective ring opening of key intermediate Boc-alpha-methyl-D-serine-beta-lactone.