Process for the preparation of oxabispidines

摘要

There is provided a process for the preparation of a compound of formula (I): which process comprises reaction of a compound of formula (II): with either a compound of formula (III): or acrylamide, followed, in the latter case, by reaction of the resulting intermediate of formula (IV): with an alcohol of formula R²-OH and an agent that promotes, or agents that in combination promote, rearrangement and oxidation of the compound of formula IV to an intermediate isocyanate, which may then react with the alcohol of formula R²-OH, and wherein R¹, R² and R¹⁶ have meanings given in the description