COMPARATIVE-STUDIES OF CATHODICALLY-PROMOTED AND BASE-CATALYZED MICHAEL ADDITION-REACTIONS OF LEVOGLUCOSENONE

Regioselective Michael addition of nitro and heterocyclic compounds to levoglucosenone, I, is effectively catalyzed by amines and also by ca thodic electrolysis. In comparison to the base-catalyzed reaction, it was found that under electrochemical conditions the reaction proceeds under milder conditions and with higher yields. Cathodically-initiated Michael addition of thiols to levoglucosenone using small currents pr oduces the previously unknown three addition product in several instan ces. The normal erythro isomer, identified as the kinetic product, ten ds to be formed when large currents are used. In contrast, slow, low c urrent electrolyses promote equilibration of the two forms so that ery thro can be converted to three by the retro reaction and readdition. A ddition of 2-naphthalenethiol to (R)-(+)-apoverbenone is also reported .