Reaction of ketone 3 with dichloromethyllithium gave 3. unique branche
d-chain dichloromethyl sugar 7 whose structure was ascertained by X-ra
y crystallography. Transformation of 7 in seven steps, involving the k
ey-intermediate alpha-azido-aldehyde 9, afforded the protected lincosa
mine analogue 14. (C) 1997 Elsevier Science Ltd.