2'-CARBAMATE TAXOL

Comparison of the conformation of 2'-carbamate taxol, {2aR-[2aalpha,4beta,4abeta,6beta,9alpha,(alphaR*,betaS*),11alpha,-12alpha,12aalpha,12balpha]}-6, 12b-bis(acetyloxy)-12-(benzoyloxy)-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-7,11-?? ethano-1H-cyclodeca[3,4]benzo[1,2-b]oxet-9-yl beta-(benzoylamino)-alpha-(carbamoyloxy)benzenepropanoate, C48H52N2O15, with the known X-ray structures of taxotere and methyl (2R,3S)-N-benzoyl-3-phenylisoserinate reveals that the most pronounced differences are in the conformation of the C13 side-chain fragment. The carbamate N atom forms two intermolecular hydrogen bonds with the taxol core and stabilizes the crystal.