Selective acetylation of per-O-TMS-protected monosaccharides.

Selective acetylation of various per-O-TMS-protected carbohydrates has been accomplished. Using a protecting group exchange strategy and microwave assistance, monosaccharides (glucose, galactose, and mannose) can be selectively acetylated producing either the 6-O-monoacetate or 1,6-O-diacetylated species. This new class of molecules can be deprotected without migration of the acetyl groups, providing useful synthetic intermediates. To demonstrate the scope of the reaction, the methodology was successfully extended to TMS-protected ceramide.