Study on Oxidative Rearrangement of Ally Alcohols Directed toward Synthesis of Taxane-Type Natural Products

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06680550
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Bioorganic chemistry
• Research Institution: Institute for Chemical Reaction Science
• Principal Investigator: KATO Michiharu Institute for Chemical Reaction Science Professor, 反応化学研究所, 教授 (00006305)
• Project Period (FY): 1994 – 1995
• Keywords: bicyclo [5.3.1] undecenones / intramolecular Barbier reaction / samarium iodide / (+) -nopinone / (+) -apoverbenone / (+) -verbenone / sulfenic acid elimination

Research Abstract

1.In order to study oxidative transformation of 1-hydroxybicyclo [5.3.1] undec-2-enes into bicyclo [5.3.1] undec-1-en-2-ones, two types of starting materials, iodides and aldehydes, were prepared, that is, 5- (5-iodopentyl) cyclohex-2-en-1-one and 5- (3-oxo-4-cyclohexenyl) hexanal from 2-cyclohexenone, and 5- [2- (2-iodoethyl) benzyl] cyclohex-2-en-1-one and 2- [(3-oxo-4-cyclohexenyl) methyl] phenylethnal from 1,4-cyclohexadienone monoethylene acetal. However unfortunately, attempted intramolecular Barbier reaction of the above two iodides and cyclization reaction of the above two aldehydes with samarium iodide proved to be unsuccessful, and desired 1-hydroxybicyclo [5.3.1] undec-2-enes were scarcely obtainable. This is mostly because of great difficulty in eight membered ring formation by use of the above reaction conditions.
2.As part of utilization of (+) -nopinone toward enantioselective synthesis of natural products, chemical transformation of (+) -nopinone into (+) -apoverbenone and (+) -verbenone was examined. After all, the phenylsulfenylation-dehydrosulfenylation method was proved to be effective for this purpose, and (+) -apoverbenone and verbenone were prepared in high overall yields by use of this methodology.