作者:Shi-Hui Chen、Vittorio Farina、Stella Huang、Qi Gao、Jerzy Golik、Terrence W. Doyle
DOI:10.1016/s0040-4020(01)85337-0
日期:1994.1
Irradiation of taxol at 280 nm in a Rayonet reactor yielded a novel pentacyclic derivative containing a new bond between C-3 and C-II. The proposed mechanism involves a triplet intermediate and the first event of the oxa-di-pi-merhane rearrangement. Taxane derivatives that lack both the benzoate at C-2 and the benzamide function at C-3' do not undergo the rearrangement, suggesting the intervention of an intramolecular energy transfer. Irradiation at 300 nm also effects extrusion of the C-9 carbonyl, yielding a ring-contracted product.