3-Butenyloxycarbonyl as a new hydroxyl protecting group in carbohydrate synthesis.

3-Butenyloxycarbonyl (Bloc) has been identified as a new hydroxyl protecting group, which can be introduced under mild conditions in high yields and selectively removed by OsO 4 /NaIO 4 /2,6-lutidine in CH 3 CN–H 2 O without affecting most commonly-used protecting groups. Moreover, this new protecting group is inert under glycosylation conditions. [ABSTRACT FROM AUTHOR]