imidazole-containing organoboronic acid catalysts is described. This catalytic process with low catalyst loading enables the introduction of a wide variety of acyl functional groups into the equatorial position of cis-vicinal diols in unprotected hexapyranosides with excellent site selectivity. This is the first example that uses a Lewis base-containing boronicacid to enhance the nucleophilicity of
The new diglycosylceramide terpioside (1a) has been isolated from the marine sponge Terpios sp. Terpioside is a diglycosylated glycosphingolipid which is the first example of a natural glycosphingolipidhaving an L-fucofuranose unit. The structure of terpioside was elucidated by extensive spectroscopic analysis, whereas chemical degradation was used to establish the nature of the alkyl chains and the