EFFICIENT TOTAL SYNTHESIS OF (1R,2R,3R,9R,9AR)-1,2,3,9-TETRAHYDROXYQUINOLIZIDINE AND ITS ENANTIOMER

被引:28
作者
RASSU, G
CASIRAGHI, G
PINNA, L
SPANU, P
ULGHERI, F
CORNIA, M
ZANARDI, F
机构
[1] CNR,IST APPL TECN CHIM AVANZATE,I-07100 SASSARI,ITALY
[2] UNIV PARMA,IST CHIM ORGAN,I-43100 PARMA,ITALY
关键词
D O I
10.1016/S0040-4020(01)81832-9
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
Concise syntheses of two enantiomeric tetrahydroxyquinolizidines, 10 and ent-10, have been achieved from D-arabinose and L-arabinose, respectively. Highly diastereoselective homologation of imine 5 (or ent-5) using 2-(trimethylsiloxy)furan provided the nine-carbon butenolide 6 (or ent-6) which was elaborated into the quinolizidine 10 (or ent-10) via a clean sequence involving, as key operations, DBU-promoted gamma-lactone to delta-lactam ring expansion (e.g. 7 to 8) and cyclodehydration of a fully-deprotected hydroxypiperidine employing Ph3P, CCl4, Et3N (e.g. 9 to 10). The procedure comprises five steps from 5 or ent-5 and provides the title quinolizidine 10 or its enantiomer ent-10 in 36-37% overall yields.
引用
收藏
页码:6627 / 6636
页数:10
相关论文
共 92 条