Electrochemical reduction mesylates

The synthesis of cyclopropanes from a,jS-unsaturated carbonyl compounds, involving bond formation between the /8-carbon and the carbonyl carbon centres, has been accomplished in an interesting manner involving electrochemical reduction of the intermediate mesylate (15) as a key stage (Scheme 4). ... 

The synthesis of organozinc compounds by electrochemical processes from either low reactive halogenated substrates (alkyl chlorides) or pseudo-halogenated substrates (phenol derivatives, mesylates, triflates etc.) remains an important challenge. Indeed, as mentioned above, the use of electrolytic zinc prepared from the reduction of a metal halide or from zinc(II) ions does not appear to be a convenient method. However, recent work reported by Tokuda and coworkers would suggest that the electroreduction of a zinc(II) species in the presence of naphthalene leads to the formation of a very active zinc capable of reacting even with low reactive substrates (equation 23)11. 

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