Cross-metathesis of methyl ester which was prepared from symbiodinolide with ethylene was performed to give the C33–C42 degraded fragment. This fragment was estimated to be (36S,40S)-diol by the modified Mosher method. Stereoselective synthesis of the (36S,40S)-diol and its diastereomer (36R,40S)-diol was achieved from l-aspartic acid. Synthetic bis-(S)- and (R)-MTPA esters which were derivatized from
由共
生物素内酯与
乙烯制得的甲酯发生交叉复分解反应,得到C33-C42降解片段。通过改进的Mosher方法估计该片段为(36 S,40 S)
-二醇。由1-
天冬氨酸实现(36 S,40 S)
-二醇及其非对映异构体(36 R,40 S)
-二醇的立体选择性合成。由(36 S,40 S)
-二醇衍生的合成双-(S)-和(R)-M
TPA酯显示的光谱数据与bis-(S)-和(R)-M
TPA酯,源自降解产物。因此,C33–C42片段的绝对立体
化学被阐明为(36 S,40 S)。