Synthesis of α-necrodol: unexpected formation of a cyclopropene

摘要

Significat 1,3-induction in intramolecular alkylidene C-H insertion is reported. Thus, exposure of ketone I to the lithium salt of (trimethylsilyl)diazomethane provides a 2.4:1.0 ratio of Iia and IIIa, which are deprotected to α-necrodol Iib and the epimeric IIIb. The 1,3-insertion product Cyclopropene IV was also formed.