2021 article
Enantioselective Synthesis of Alkylidenecyclobutanones via Formal Vinylidene Insertion into Cyclopropanone Equivalents
Poteat, C., & Lindsay, V. (2021, June 29). (Vol. 6). Vol. 6.
open access via doi.org (repository)
Source: ORCID
Added: June 30, 2021
1-Sulfonylcyclopropanols are employed here as efficient cyclopropanone equivalents in a formal vinylidene insertion process, providing the first general synthetic route to enantioenriched alkylidenecyclobutanones. The addition of an alkenyl-Grignard reagent to the cyclo-propanone leads to an alkenylcyclopropanol capable of electrophilic activation by NBS, triggering a regio- and stereospecific 1,2-migration and the formation of a brominated cyclobutanone intermediate prone to elimination. The parent β-amino ketone can also be accessed by one-pot aza-Michael addition to the resulting product, and activation of the alkenylcyclopropanol intermediate with other electrophiles such as HCl or mCPBA led to the controlled formation of a variety of chiral cyclobutanones and γ-lactones via alternative pathways.