Improved Synthesis of γ-Lactones from Cyclopropyl Cyanoesters

Abstract

Cyclopropyl cyanoesters 2 were reliably converted to γ-lactones 4 on treatment with aqueous sulfuric acid. The cyanoesters could be easily prepared from ketones or aldehydes in two steps, making this process particularly attractive from an efficiency standpoint.

Keywords:

• Condensation
• cyclopropyl cyanoester
• Knoevenagel
• lactone
• ring expansion

ACKNOWLEDGMENTS

The authors thank Jennifer Davoren, Amy Dounay, Andrew Flick, Christopher O'Donnell, and Suvi Simila for helpful suggestions.

Notes

^a Isolated yields. For procedures, see Experimental section.