Use of Cyclic Allylic Bromides in the Zinc–Mediated Aqueous Barbier–Grignard Reaction

Gary W Breton,Suzanne M Perala,Brian P Conrad,Christine A Hughey,John H Shugart

doi:10.3390/60800655

Abstract

The zinc–mediated aqueous Barbier–Grignard reaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90%) and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic ketones. Regioselectivity was high when some substituted cyclic allylic bromides were investigated.

Highlights

The synthesis of homoallylic alcohols via the reaction of cyclic and acyclic allylic organometallic compounds with aldehydes and ketones is an important process in synthetic organic chemistry [1]
Bromide 1b reacted with substituted benzaldehydes to afford adducts in good yields and stereoselectivities
Reaction with the non–aromatic aldehydes heptaldehyde and isobutyraldehyde, afforded very low stereoselectivity the mixtures of diastereomers were obtained in reasonable yield

Summary

Introduction

The synthesis of homoallylic alcohols via the reaction of cyclic and acyclic allylic organometallic compounds with aldehydes and ketones is an important process in synthetic organic chemistry [1]. Bromide 1b reacted with substituted benzaldehydes to afford adducts in good yields and stereoselectivities (see Table 1).

Results

Conclusion