Claims
- 1. A process for forming a 4-ketocyclopentene compound comprising reducing a 1-carbohydrocarbyloxy-2-keto-4-hydroxy-5-cyclopentene compound by contacting with a metal and decarboxylating the resulting reaction product by contacting with a mixture of an organic acid and an inorganic halide compound selected from the group consisting of zinc dichloride and zinc dibromide.
- 2. The process of claim 1 wherein the metal is zinc, the organic acid is acetic acid, and the 1-carbohydrocarbyloxy-2-keto-4-hydroxy-5-cyclopentene and 4-ketocyclopentene compounds correspond to the formula:
- 3. The process of claim 1 wherein 2,3-dihydro-2-oxo-1H-cyclopenta(l)phenanthrene is prepared from a C1-20 alkyl 3,3a-dihydro-3a-hydroxy-2-oxo-2H-cyclopenta(l)phenanthrene-1-carboxylate.
- 4. 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:
- 5. A process for preparing a functionalized cyclopentadienyl compound by reducing a ketone to form an alcohol, replacing the hydroxyl functionality of the alcohol under substitution conditions with a leaving group, and reacting the leaving group substituted cyclopentene compound with at least two equivalents of a base and a source of a functionalizing ligand, said process comprising in combination a reduction, substitution, elimination, deprotonation and replacement operation illustrated schematically as follows:
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. application Ser. No. 09/443,394, filed Nov. 19, 1999, which claims benefit of priority from provisional application 60/122,614, filed Mar. 3, 1999.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60122614 |
Mar 1999 |
US |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09443394 |
Nov 1999 |
US |
Child |
09885808 |
Jun 2001 |
US |