Enantioselective Reduction of meso-Cyclic-1,2-dicarboxylic Anhydrides and 1,2-Dicarboximides: Asymmetric Synthesis of Bicyclic Lactones and Hydroxylactams.
作者:Kenji MATSUKI、Hirozumi INOUE、Akihiko ISHIDA、Mikio TAKEDA、Masako NAKAGAWA、Tohru HINO
DOI:10.1248/cpb.42.9
日期:——
Chiral bicyclic lactones (3, 8, 9) and bicyclic hydroxylactams (10-13) were synthesized by highly enantioselective reduction of meso-cyclic-1, 2-dicarboxylic anhydrides (1, 4) and meso-cyclic-1, 2-dicarboximides (2) with lithium aluminum hydride (LiAlH4)-alcohol(ROH)-(R)- or (S)-1, 1'-bi-2-naphthol complex [(R)- or (S)-BINAL-H(ROH)]. Treatment of the hydroxylactams (10-13) with triethylsilane (Et3SiH) and trifluoroacetic acid (CF3CO2H) gave chiral bicyclic lactams (14, 15) in quantitative yields. Removal of the N-4-methoxyphenyl group of the lactams (14, 15) with cerium(IV) ammonium nitrate (CAN) proceeded smoothly to give the corresponding N-unsubstituted lactams (16, 17) in high optical purity.
手性双环内酯(3、8、9)和双环羟基内酰胺(10-13)是通过对meso-环状-1,2-二羧酸酐(1、4)和meso-环状-1,2-二羧酰胺(2)进行具有高对映选择性的还原反应,使用锂铝氢化物(LiAlH4)-醇(ROH)-(R)或(S)-1,1'-双-2-萘醇复合物[(R)或(S)-BINAL-H(ROH)]合成的。对羟基内酰胺(10-13)进行三乙基硅烷(Et3SiH)和三氟乙酸(CF3CO2H)的处理,得到了手性双环内酰胺(14、15),产率为定量。在高光学纯度下,用铈(IV)铵硝酸盐(CAN)顺利去除内酰胺(14、15)中的N-4-甲氧基苯基基团,得到相应的N-不取代内酰胺(16、17)。