Methods for the acylation of maytansinol

摘要

Disclosed is a method of preparing an amino acid ester of maytansinol by reacting maytansinol with an N-carboxyanhydride of an amino acid (NCA) in the presence of a drying agent. Also disclosed is an improved method of preparing an amino acid ester of maytansinol in which a nucleophile is added to the reaction mixture after completion of the reaction between maytansinol and an N-carboxyanhydride of an amino acid.

主权项

1. A method of preparing a compound represented by the following formula: wherein R1 is methyl; and R2 is methyl, the method comprising: reacting maytansinol with an N-carboxyanhydride in a reaction mixture additionally comprising a base, a drying agent and a Lewis acid, wherein the N-carboxyanhydride is represented by the following formula:thereby forming the compound of Formula (I).