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Preparation of α,α‐Dibromocyclobutanones from Olefins: A simple procedure for the regioselective functionalization of olefins
Author(s) -
Chaumeil Hélène,
Le Drian Claude
Publication year - 1996
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19960790416
Subject(s) - chemistry , regioselectivity , surface modification , halogenation , bromide , cycloaddition , yield (engineering) , organic chemistry , catalysis , materials science , metallurgy
Dibromoketene is prepared by in‐situ Zn dehalogenation of tribromoacetyl bromide in the presence of POCl 3 . Under these conditions, the cycloaddition of dibromoketene with olefins 5 yields α,α‐dibromocyclobutanones 2 , which are cleaved with alkoxides to yield β‐dibromomethyl esters 4 . Several examples are given. For monosubstituted olefins, the functionalization is regioselective, the methoxycarbonyl group being introduced at the terminal C‐atom.