Total Synthesis of (±)‐Infuscol A and (±)‐Cuprenenol

Abstract

Total synthesis of the nonaromatic cuparenoid sesquiterpenes (±)‐infuscol A and cuprenenol, and (±)‐infuscol B and neocuprenenol isolated from the Japanese liverwort Jungermannia infusca has been accomplished. Two ring‐closing metathesis reaction based strategies have been developed for the generation of the key intermediate of the sequence.

Keywords:

• Claisen rearrangement
• Cuparanes
• Ring‐closing metathesis reaction
• Terpene synthesis

Acknowledgments

We thank Professors Y. Asakawa and F. Nagashima for providing the copies of the NMR spectra of natural infuscols A and B, cuprenenol, and neocuprenenol; and C.S.I.R., New Delhi for the award of a research fellowship to G.S.