Hydroalumination-Brominolysis of Vinylalkynols: A Novel Entry to (E)- and (Z)-Bromoalkadienols, and Bromoallenols

2000/12/20 by Hovhannes Gharibian, Gulnara Palikyan, Shaliko H. Badanyan +4
Chemistry · #Catalytic Alkyne Reactions #Synthetic Organic Chemistry Methods #Oxidative Organic Chemistry Reactions

paper · doi:10.1002/1522-2675(20001220)83:12<3291::aid-hlca3291>3.0.co;2-p

Abstract

Hydroalumination-brominolysis of vinylacetylenic alcohols 1 – 4 provides a novel entry to synthetically useful (E)- and (Z)-bromoalkadienols, and bromoallenols, which are otherwise hardly accessible. An electrophilic cleavage of cyclic intermediate A follows competing mechanistic pathways, giving rise to isomeric (Z)-bromodienols 5 – 8 and allenic alcohols 9 – 12. The latter are stereoselectively converted to (E)-bromoalkadienols 13 – 16 by CuBr-catalyzed anionotropic rearrangement.

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