Tri-n-butyltin cuprate as a tool for the preparation of stannyl derivatives of carbohydrates

Abstract

Reaction of tri-n-butyltin cuprate with sterically hindered allylbromides 10(E) and 10(Z) derived from D-galactose led exclusively to S N 2 products - allyl tributystannyl sugars 11(E) and 11(Z) in good yield and with retention of the configuration of the double bond. Reaction of ‘Bu 3 SnCu’ with less sterically hindered allyl derivatives 5a and 5b (derived from D-glucose) gave a mixture of S N 2 and S N 2′ products ( 6 and 7 respectively). Treatment of methyl 2,3,4-tri-O-benzyl-6-O-mesyl-α-D-glucopyranoside ( 13 ) with ‘Bu 3 SnCu’ afforded organotin 14 , which was further converted into an open-chain unsaturated aldehyde 15 (in the presence of zinc chloride). Reaction of ‘Bu 3 SnCu’ with sugar aldehydes provided stannyl carbinols, while with α,β-unsaturated sugar aldehydes the 1,4-addition products are formed. Several sugar-tin derivatives were prepared from tri- n -butyltin cuprate and appropriate sugar nucleophiles. Application of these compounds in organic synthesis is also presented.