Patent ID: 6090168
Filing Date: 2000-07-18
Classification: C07C

Abstract:
A process for preparing a compound of formula III: ##STR15## wherein: R.sup.2 is NHCH(CO.sub.2 R.sup.3)CH.sub.2 CH.sub.2 CO.sub.2 R.sup.3 or OR.sup.3 ;R.sup.3 is independently at each occurrence a carboxy protecting group; andX is a bond or C.sub.1 -C.sub.4 alk-diyl;comprising:reacting a compound of formula IV: ##STR16## wherein: X and R.sup.2 are defined above for formula III;M is a metal cation; andn is 1 or 2;with a trialkylsilyl halide in a solvent.