Insight on p‐Acetoxybenzyl Carbonate as an Orthogonal Hydroxyl Protecting Group in Oligosaccharide Synthesis

This study describes the utility of p‐acetoxybenzyl carbonate (ABC) group for the protection of hydroxyl functions. This hydroxyl protecting group can be easily prepared using inexpensive commercially available 4‐hydroxybenzyl alcohol as the starting material. The ABC group can be selectively removed through ytterbium(III) triflate‐catalyzed transesterification at room temperature without affecting commonly used acid‐cleavable protecting groups, such as tert‐butyldimethylsilyl (TBDMS), p‐methoxybenzyl (PMB), acetonide, and benzylidenes. Notably, the ABC protecting group is stable under glycosylation conditions in oligosaccharide synthesis.