Abstract: An improved process for the preparation in high yields of a compound of the formula ##STR1## wherein R is an optionally substituted phenyl group, Y is selected from the group consisting of Me and a hydrocarbon, Me is a metal cation and E is selected from the group consisting of hydrogen and a metal cation comprising reacting a compound of the formula ##STR2## wherein Q is selected from the group consisting of hydrogen and a silyl protecting group, Rz is an optionally substituted phenyl with the proviso that any hydroxy group present on the phenyl are replaced by --OQz, wherein Qz is a silyl protecting group and Ez is a carboxyl protecting group, with a compound of the formula ##STR3## wherein Z is a halogen and X is selected from the group consisting of OY and Z at low temperatures under anhydrous conditions and carefully hydrolyzing the resulting product either with just enough water to remove protecting groups and hydrolyze the Z groups to hydroxy groups and, still under anhydrous conditions, reacting the c