Patent ID: 6417405
Filing Date: 2002-07-09
Classification: C07C,C07F

Abstract:
A process for preparing a cyclopententadiene or substituted cyclopentadiene compound, the steps of the process comprising reducing a ketone to form an alcohol, replacing the hydroxyl functionality of the alcohol under substitution conditions with a leaving group, and deprotonating the resulting product under base induced elimination conditions to form the cyclopentadiene compound, wherein the ketone, alcohol, substituted product and cyclopentadiene correspond to the following formulas, and the process corresponds to the following scheme: wherein: R1 independently each occurrence is hydrogen, hydrocarbyl, silyl, germyl, halide, or halo- substituted hydrocarbyl, said R1 group having up to 40 atoms not counting hydrogen atoms, and optionally two or more of the foregoing adjacent R1 groups may together form a divalent derivative thereby forming a saturated or unsaturated fused ring or multiple ring system, and further optionally one or more of the carbons of R1 in any of the so formed rings may be replaced by a nitrogen, boron, phosphorus or sulfur atom; Lg is a ligand group that is subject to base induced elimination, and the ketone is prepared by reducing a 1-carbohydrocarbyloxy-2-keto-4-hydroxy-5-cyclopentene compound by contacting with a metal and decarboxylating the resulting reaction product by contacting the reaction mixture with a mixture of an organic acid and an inorganic halide compound.