Stereochemical Control in Microbial Reduction. 9. Diastereoselective Reduction of 2-Alkyl-3-oxobutanoate with Bakers’ Yeast
作者:Kaoru Nakamura、Takehiko Miyai、Ashish Nagar、Shinzaburo Oka、Atsuyoshi Ohno
DOI:10.1246/bcsj.62.1179
日期:1989.4.15
Bakers’ yeast reduces esters of 2-alkyl-3-oxobutanoic acid (CH3COCHRCO2R′; R=methyl, ethyl, propyl, propargyl, and allyl) into the corresponding (S)-hydroxy esters with exclusive stereoselectivity, while the configuration at the 2-position of the hydroxy esters is either S (anti) or R (syn) depending on the structure of the alkoxyl group in the carboalkoxyl moiety of the ester. Oftenly, the stereoselectivity
面包师的酵母将 2-烷基-3-氧代丁酸(CH3COCHRCO2R';R=甲基、乙基、丙基、炔丙基和烯丙基)的酯还原为相应的(S)-羟基酯,具有独特的立体选择性,而在 2羟基酯的-位是S(反)或R(syn),这取决于酯的碳烷氧基部分中烷氧基的结构。通常,关于 2 位的立体选择性并不令人满意。一般来说,叔丁酯的还原在产物中占主导地位,而 1,1-二甲基丙酯的还原则发挥顺式优势。从酯的合理构象的角度讨论了这两种酯在非对映选择性方面的显着差异。