Alpha-vinylation and fragmentations of cyclobutanones

Cyclobutanones are an important class of compounds that are often used as intermediates for the synthesis of various natural products. Owing to their inherent ring strain, they can undergo various types of reactions including ring expansions, rearrangements, fragmentations and alpha functionalization. Thus, functionalized cyclobutanones can act as junctions to access other synthetically useful compounds. The ability to functionalize cyclobutanones is highly desirable from a synthetic standpoint. Previously our laboratory had reported palladium catalyzed alpha arylation of cyclobutanones. These alpha arylated cyclobutanones were then fragmented and used to prepare various natural products. Based on this precedence we sought to expand this methodology to include vinyl groups. We then sought to study various fragmentation reactions of these vinylated substrates to increase structural complexity. Additionally, reduction-rearrangement and aldol functionalization strategies were also investigated.