Patent ID: 7468447

Claim:
A process for the preparation of an diastereoisomeric mixture of the following formula: comprising the steps of: (1) subjecting a compound of structure IV to Darzen's condensation to provide a compound of structure V (2) saponifying the compound of structure V to provide a compound of structure VI (3) subjecting the compound of structure VI to pyrolysis to provide a compound of structure VII (4) subjecting a compound of structure VII to Knoevenagel reaction with cyanoacetic acid to provide a compound of structure VIII (5) providing a compound of structure IX by subjecting compound VIII to ring closing reaction (6) saponifying the compound of structure IX to provide a compound of structure X (7) cyclizing the compound of structure X to provide a compound of structure XI (8) reducing the compound of structure XI to provide a structure XII (9) subjecting a diastereoisomeric mixture of the structure XII to ring closing reaction to provide the diastereoisomeric mixture of structure I: