Asymmetric routes toward polyhydroxylated pyrrolidines: Synthesis of 1,4-dideoxy-1,4-imino-D-galactitol and 1,4-dideoxy-1,4-imino-D-glucitol

Herein the total synthesis of the pyrrolidine alkaloids 1,4-dideoxy-1,4-imino-D-galactitol and its diastereoisomer 1,4-dideoxy-1,4-imino-D-glucitol is described, starting from a common optically active precursor. The key step in our approach was the double diastereoselection in the asymmetric dihydroxylation of chiral vinyl azido alcohols, obtained by means of two different regio-and stereo selective nucleophilic openings of the corresponding chiral vinyl epoxide. (C) 2016 Elsevier Ltd. All rights reserved.