(1) is a polyol macrolide with a molecular weight of 2859 mu. As one of the degradation reactions, cross-metathesis of 2, which is a methyl ester of 1, with ethylene was performed to give the C33–C42 degraded fragment 4. The absolute configuration of 4 was estimated to be (36S,40S) by Mosher method. Stereoselective synthesis of 4 was achieved in 14 steps from l-aspartic acid. Synthetic bis-(S)- and
共生二
生物内
酯(1)是分子量为2859μm的多元醇大环内
酯。作为降解反应中的一个,的交叉复分解2,这是一个
甲基酯1,与
乙烯进行,得到C33-C42片段降解4。Mosher法估计4的绝对构型为(36 S,40 S)。从1-
天冬氨酸分14步完成4的立体选择性合成。合成的双-(S)-和(R)-M
TPA酯的光谱数据与双-(S)-和(R)-M
TPA酯衍生自降解片段4。因此,阐明了4的绝对立体
化学是(36 S,40 S)。