Scalable process for the preparation of a rapamycin 42-ester from a rapamycin 42-ester boronate

摘要

A scalable process for the preparation of a rapamycin 42-ester by reacting a rapamycin 42-ester boronate with a diol and purifying crude rapamycin 42-ester by recrystallization and treatment with a diol is provided. Also provided is a method for isolating and purifying a rapamycin 42-ester boronate from mother liquors comprising acetone and rapamycin contaminants.