Oxy-Cope rearrangements of bicyclo[3.2.0]heptenones. Synthesis of bicyclo[4.2.1]non-1(4)-en-6-ones and bicyclo[5.2.1]dec-1(10)-en-5-ones

Sharad K. Verma, Que H. Nguyen, James M. MacDougall, Everly B. Fleischer, Harold W. Moore

Research output: Contribution to journalArticlepeer-review

Abstract

6-exo-Methylbicyclo[3.2.0]hepten-7-ones and their 2-alkylidene analogues are readily prepared from dialkyl squarates. These compounds undergo facial oxy-Cope ring expansions upon treatment with vinyllithium; the former leads to bicyclo[4.2.1]non-1(4)-en-6-ones and the latter to the first examples of bicyclo[5.2.1]dec-1(10)-en-5-ones, compounds having exceptionally strained bridgehead double bonds. The transformations are controlled by the 6-exo- methyl group in the starting material along with the substituent at position- 1 (bridgehead) which force attack of the lithium reagent from the concave face of the starting material, thus allowing the cyclopentenyl or alkylidene groups to participate in the sigmatropic event.

Original languageEnglish (US)
Pages (from-to)3379-3386
Number of pages8
JournalJournal of Organic Chemistry
Volume65
Issue number11
DOIs
StatePublished - Jun 2 2000

ASJC Scopus subject areas

  • Organic Chemistry

Fingerprint Dive into the research topics of 'Oxy-Cope rearrangements of bicyclo[3.2.0]heptenones. Synthesis of bicyclo[4.2.1]non-1(4)-en-6-ones and bicyclo[5.2.1]dec-1(10)-en-5-ones'. Together they form a unique fingerprint.

Cite this