Stereo-controlled approach to pyrrolidine iminosugar C-glycosides and 1,4-dideoxy-1,4-imino-l-allitol using a d-mannose-derived cyclic nitrone
作者:Omprakash P. Bande、Vrushali H. Jadhav、Vedavati G. Puranik、Dilip D. Dhavale、Marco Lombardo
DOI:10.1016/j.tetlet.2009.09.139
日期:2009.12
Intramolecular N-alkylation of 2,3-O-isopropylidene-5-O-methanesulfonyl-6-O-t-butyldimethylsilyl-d-mannofuranose-oxime 7 afforded a five-membered cyclic nitrone 9, which on N–O bond reductive cleavage followed by deprotection of –OTBS and acetonide functionalities gave 1,4-dideoxy-1,4-imino-l-allitol (DIA) 3. Addition of allylmagnesium chloride to nitrone 9 afforded α-allylated product 10a in high
分子内N-烷基化的2,3- ø异亚丙基-5- ö甲磺酰基- 6- ø -吨-butyldimethylsilyl- d -mannofuranose肟7,得到的五元环状硝酮9,其上ñ - ö键还原裂解然后对–OTBS和丙酮化物进行脱保护,得到1,4-二脱氧-1,4-亚氨基-1-烯丙醇(DIA)3。将烯丙基氯化镁添加到硝酮9中可得到高非对映选择性的α-烯丙基化产物10a,从而易于进入N除去保护基后,用-羟基-C1-α-烯丙基取代的吡咯烷亚氨基糖4a,而在10a中进行N - O键还原裂解,得到C1-α-烯丙基-吡咯烷亚氨基糖4b。