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中文摘要：
报道了多用途的吡咯烷类氮杂糖中间体6的不对称合成．起始原料（2R，3R，4S）-2-苄氧甲基-3，4-二苄氧基-5-氧代吡咯烷-1-羧酸叔丁酯（8）由手性合成砌块酒石酸酰亚胺7按照先前本实验室报道的方法经4步得到．活化的酰胺8经乙烯基加成、立体选择性还原、环化、氧化断裂双键成醛以及还原醛成醇等步骤得到了氮杂糖中间体（2R，3R，4R，5R）-2-羟甲基-3，4-二苄氧基-5-苄氧甲基吡咯烷-1-羧酸叔丁酯（6）．从活化的酰胺8出发，经过5步反应，立体选择性地合成了氮杂糖中间体6，总产率46％．中间体6可用于多个吡咯烷类氮杂糖的合成．
英文摘要：
A convenient asymmetric synthesis of the protected polyhydroxylated pyrrolidine 6, a key intermediate for the synthesis ofpyrrolidine azasugars is reported. The synthesis started with tert-butyl （2R,3R, 4S）-3,4-bis（benzyloxy）-2-（benzyloxymethyl）-5-oxopyrrolidine-l-earboxylate 8, which was derived from the fully protected D-tartarimide 7 in 62% overall yield. Addition of vinylmagnesium bromide with compound 8 at --78℃ for 2 h afforded the aza-hemiacetal 9a and its tautomer 9b, which, without separation, were treated with NaBH4/CeCl3 · H2 O to give the reduced product 10 as the only observable diastereomer in 90 %yield. Under the mesylation conditions （MsC1： 2.0 equiv, Et3 N： 3 equiv, CH2 Cl2, 12 h）, compound 10 was converted directly to the eyclized product 12 in 89% yield. Oxidative cleavage （RuCl3-NalO4, MeCN/H2 O, rt） of the olefin 12 followed by reduction of the crude aldehyde 13 with NaBH, afforded the desired pyrrolidine 6,tert-butyl （2R,3R,4R,5R）-3,4-his（benzyloxy）-2-（benzyloxymethyl）-5-（hydroxy-methyl） pyrrolidine-l-carboxylate in 58% overall yield from 12. Thus, using vinyl group as a synthetic equivalent of hydroxymethyl group, pyrrolidine 6 was synthesized from building bloek 8 in 46% overall yield. Pyrrolidine 6 is a key intermediate for the synthesis of DMDP and other pyrrolidine azasugars.
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