Regiospecific 4,6-Functionalization of Pyranosides via Dimethylboron Bromide-Mediated Cleavage of Phthalide Orthoesters
摘要:
An efficient strategy for regiocontrolled differentiation of the 4,6-positions of pyranosides has been developed using dimethylboron bromide-mediated cleavage of phthalide orthoesters. The reaction proceeds under mild conditions, is tolerant of additional acetal functionality, and produces a benzoate bearing suitable functionality for intramolecular assisted cleavage in the presence of SAc, OAc, and NHAc groups.