An Expedient Synthesis of Allylic/Secondary Bromides from Dehydration of Tertiary-β-bromo Alcohols

Abstract

Tertiary-β-bromo alcohols, derived from simple monoterpenes and olefins, react with BF₃.OEt₂ in refluxing benzene in 1–2 h to afford the corresponding allylic/secondary bromides in 45–90% yield. In case of substrates containing olefinic or hydroxyl groups, formation of cyclic ethers was observed.

Keywords:

• Tertiary-β-bromo alcohols
• Dehydration
• BF₃·OEt₂
• Allylic bromides
• Secondary bromides

Acknowledgment

BKB is thankful to Council of Scientific and Industrial Research, New Delhi, India, for the fellowship. Assistance of Sophisticated Instrument Facility, Indian Institute of Science, Bangalore, India in recording of ¹H and ¹³C NMR spectra is gratefully acknowledged.