C-Allylation of 1- and 6-Bromosugars with Allylic Sulfides and Sulfones.
Reaction of the bromosugars 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide (1), methyl 2,3-anhydro-6-bromo-6-deoxy-alpha-D-allopyranoside (2), and methyl 2,3-anhydro-4-O-benzoyl-6-bromo-6-deoxy-alpha-D-allopyranoside (3) with the allylic sulfides and sulfones 4-9 in the presence of hexabutyldistannane under photolytic conditions gave the corresponding alpha-C-allyl galactosides 10-12 and the 6-C-allylated epoxysugars 13, 15, and 16 in 61-90% yield.
Pontén
Fritiof
F
Organic Chemistry 2, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
Magnusson
Göran
G