C-Allylation of 1- and 6-Bromosugars with Allylic Sulfides and Sulfones

Abstract
Reaction of the bromosugars 2,3,4,6-tetra-O-acetyl-α-d-galactopyranosyl bromide (1), methyl 2,3-anhydro-6-bromo-6-deoxy-α-d-allopyranoside (2), and methyl 2,3-anhydro-4-O-benzoyl-6-bromo-6-deoxy-α-d-allopyranoside (3) with the allylic sulfides and sulfones 4−9 in the presence of hexabutyldistannane under photolytic conditions gave the corresponding α-C-allyl galactosides 10−12 and the 6-C-allylated epoxysugars 13, 15, and 16 in 61−90% yield.