Synthesis of C‐2 Taxol Analogues

Nucleophilic ring opening of cyclic carbonates 1 leads regioselectively to the less substituted ester 2. Moreover, for molecules with several carbonyl groups the reaction is chemoselective: In a taxol precursor the carbonate group and not one of the three additional carbonyl groups was attacked; the resulting esters were converted into taxol analogues that displayed differing cytotoxicities. (Figure Presented.)