Patent ID: 6265587
Filing Date: 2001-07-24
Classification: C07C,C07D,C07F

Abstract:
Process for the preparation of taxane side chain precursors in which a cis-.beta.-arylglycidate derivative of general formula I ##STR47##in whichAr represents an aryl radical andR represents a hydrocarbon radical, preferably a linear or branched alkyl or a cycloalkyl optionally substituted by one or more alkyl groups,is converted, so as to regio- and stereospecifically introduce the .beta.-Nalkylamide and the (-hydroxyl or their cyclic precursors in a single stage by a Ritter reaction, which consists either:a of the direct synthesis of a linear chain by reacting a cis-.beta.-arylglycidate derivative of general formula I defined above with a nitrile of formulaR.sub.2 --CNin whichR.sub.2 represents an aryl radical, in the presence of a protonic acid and of water, in order to obtain a .beta.-arylisoserine derivative of general formula IIa, ##STR48##in which Ar, R and R.sub.2 are defined above; orb of the direct synthesis of a cyclic chain by reacting a cis-.beta.-arylglycidate derivative of general formula I defined above with a nitrile of formulaR'.sub.2 --CNin whichR'.sub.2 represents R.sub.2 defined above or a lower alkyl or lower perhaloalkyl radical, such as trichloromethyl,in the presence of a Lewis acid or of a protonic acid, in anhydrous medium, in order to obtain the oxazoline of general formula IIb ##STR49##in which Ar, R and R'.sub.2 are defined above.