Desymmetrization of 3-dimethyl(phenyl)silyl glutaric anhydride with Evans’ oxazolidinone: an application to stereocontrolled synthesis of the antifungal agent (+)-preussin
作者:Rekha Verma、Sunil K. Ghosh
DOI:10.1039/a808840c
日期:——
A stereoselective total synthesis of (+)-preussin (1) has been achieved from the σ-symmetric 3-dimethyl(phenyl)silyl substituted glutaric anhydride 4 featuring its desymmetrization using Evans’ oxazolidinone 10. The first homochiral intermediate, the glutarate half-ester 9 was obtained from both the diastereoisomeric acids 11a and 12a in a convergent fashion. The dimethyl(phenyl)silyl group is not
(+)-普鲁酶(1)的立体选择性全合成是由σ-对称的3-二甲基(苯基)甲硅烷基取代的戊二酸酐4实现的,其特征在于使用Evans的恶唑烷酮10进行不对称化。从非对映异构酸11a和12a以收敛的方式获得酯9。二甲基(苯基)甲硅烷基不仅起掩蔽的羟基的作用,而且还限制了消除反应并促进了库尔蒂斯反应。它还stereodirects烯醇酯18的烷基化和中间Δ的氢化1吡咯啉5。