(2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-3-phenylpropionate 4-acetoxy-2?-benzoiloxy-5� ,20-epoxy-1, 7�, 10�-trihydroxy-9-oxo-taks-11 -en-13?-yl solvates, a method for their production and application thereof

摘要

The present invention provides solvates of 4-acetoxy-2a-benzoyloxy-5ss,20-epoxy-1,7ss,10ss- trihydroxy-9-oxo-tax-11 -en-13a-yl (2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-3- phenylpropionate and C2-3-alkyl esters of formic acid, process of their preparation and their use in the synthesis of the pharmaceutically pure 4-acetoxy-2a-benzoyloxy-5ss,20-epoxy- 1,7ss,10ss-trihydroxy-9-oxo-tax-11-en-13a-yl (2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy- 3-phenylpropionate.