ALPHA-AMINO-ACIDS AS CHIRAL EDUCTS FOR ASYMMETRIC PRODUCTS - ALKYLATION OF N-PHENYLFLUORENYL ALPHA-AMINO KETONES - SYNTHESIS OF OPTICALLY PURE ALPHA-ALKYL CARBOXYLIC-ACIDS
ALPHA-AMINO-ACIDS AS CHIRAL EDUCTS FOR ASYMMETRIC PRODUCTS - ALKYLATION OF N-PHENYLFLUORENYL ALPHA-AMINO KETONES - SYNTHESIS OF OPTICALLY PURE ALPHA-ALKYL CARBOXYLIC-ACIDS
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DOI：
10.1021/ja00230a027
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发表时间：
1988-10-26
影响因子：
15
通讯作者：
RAPOPORT, H
中科院分区：
文献类型：
--
作者：
LUBELL, WD;RAPOPORT, H
N-(9-苯基芴-9-基)氨基酮的区域选择性烯醇化和烷基化提供了α''-烷基支化的α-氨基酮的非对映异构体混合物。非对映异构体的分离提供了>99％对映体纯的α”-烷基支化的α-氨基酮，其可以在α”-碳处差向异构化。非对映体纯的烷基化产物的脱保护和随后的氧化降解提供对映体纯的α-烷基取代的羧酸。通过利用 L-丙氨酸作为一碳手性结构单元的七步工艺合成了对映体纯度 >99% 的 α-甲基戊酸和 α-苯基丙酸。
Regioselective enolization and alkylation of N-(9-phenylfluoren-9-yl)amino ketones provides diastereomeric mixtures of .alpha.''-alkyl branched .alpha.-amino ketones. Separation of the diastereomers provides >99% enantiomerically pure .alpha.''-alkyl branched .alpha.-amino ketones which can be epimerized at the .alpha.''-carbon. Deprotection and subsequent oxidative degradation of the diastereomerically pure alkylated products provide enantiomerically pure .alpha.-alkyl-substituted carboxylic acids. .alpha.-Methylpentanoic acid and .alpha.-phenylpropanoic acid are synthesized in >99% enantiomeric purity from this seven step process that utilizes L-alanine as a one-carbon chiral building block.