Figure 1.

Structures of Taxol, the related semi-synthetic drug Taxotere, and their respective precursors. Ac and Bz denote acetyl and benzoyl groups, respectively. The taxane A ring in this figure is illustrated as found in much of the earlier literature. Subsequent renderings illustrate the A ring as suggested by Kingston et al. (1993) to more accurately depict the 16β- and 17α-methyl groups.