Synthesis of Fused Tetrahydrofuran‐γ‐lactone Motifs via One‐Pot Ring Expansion of Cyclopropane Rings

Abstract

An efficient method for constructing fused tetrahydrofuran‐γ‐lactone scaffolds, such as 8, is presented. Key to this strategy is an acid‐catalyzed ring expansion of cyclopropyl precursor 6 that proceeds in the presence of MeSO₃H in acetone and produces the desired bicyclic system in good to excellent yields.

Keywords:

• Cyclopropanation
• Ring expansion
• Tetrahydrofuran‐γ‐lactone
• Bicyclic system

Acknowledgment

Financial support from the NIH (CA086079) is gratefully acknowledged. We also thank Dr. P. Gantzel (UCSD, x‐ray Facility) for the reported crystallographic structure.

Notes

^aThe crystallographic data for structure 17 have been deposited at the Cambridge Crystallographic Data Centre as supplementary publication No: CCDC 212319. These data can be obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html.