81388-76-3Relevant articles and documents
Preparation and Rearrangement of 1,2-Dialkenylcyclobutanols. A Useful Method for Synthesis of Substituted Cyclooctenones
Gadwood, Robert C.,Lett, Renee M.
, p. 2268 - 2275 (2007/10/02)
The syntheses and anionic oxy-Cope rearrangements of 1,2-dialkenylcyclobutanols are reported.Reaction of 2-methyl-2-(2-methylpropen-1-yl)-1-cyclobutanone (1) with vinyl-, isopropenyl-, or isobutenyllithium led to formation of cyclobutanols 2a-c.Treatment with potassium hydride induced rearrangement to Z and E cyclooctenones 3a-c and 4a,c.Reaction of 5-methylenespirononan-1-one (8) with the same alkenyllithium reagents afforded directly a mixture of rearranged and ring-opened products (11a-c and 12a-c).Reaction of spironon-5-en-1-one (17) with vinyl- or isopropenylmagnesium bromide produced a mixture of diastereomeric cyclobutanols 18a,b and 19a,b which underwent anionic oxy-Cope rearrangement to bicycloundec-1(11)-en-4-ones 20a,b in high yield.A mechanism for the rearrangement of stereodistal 1,2-dialkenylcyclobutanols is proposed.