Analysis of the H-1 NMR data of paclitaxel in comparison with its oxetane r
ing-opened analogue D-secopaclitaxel suggests that the oxetane moiety (D-ri
ng) of paclitaxel serves as a conformational lock for the diterpene moiety
and the C13 side chain. (C) 1999 Elsevier Science Ltd. All rights reserved.