MODEL STUDIES IN THE TAXANE DITERPENE SERIES - Part. I

Article abstract of DOI:10.1016/S0040-4020(01)87316-6

Photochemical <2 + 2> cycloaddition of enol acetate 10a to cyclohexene led to a 3:1 mixture of the tetracyclic photoadducts A and B which, trough reverse aldol reactions, under mild alkaline conditions produced two compounds: a tetracyclic ketone 13 and a tricyclic diketone 14.Hydrolytic cleavage in methanolic hydrochloric acid of 15 and 16 resulting from irradiation of the enol ether 10b to cyclohexene gave rise to the rearranged tricyclic diketone 14 only.The trans stereochemistry 3α, 8β of the fused-ring system in 14, established by X-ray measurements, is different from the stereochemistry of the naturally occuring taxane derivatives.Ejus elementi compositionem quod vim habet in taxo baccata, photochimiae beneficio, quidam in exemplo simpliciore reddito experti sunt.Perincommode tamen accidit ut materiae ita quaesitae figura dissimilis sit ejus rei natura praebitae.