ELECTROLABILE PROTECTING GROUPS FOR KETONES - THE ELECTROCHEMICAL REDUCTIVE CLEAVAGE OF 1,3-DIOXOLANES AND 1,3-DIOXANES CONTAINING NITRO ORHALO GROUPS

The electroreductive cleavage of 4-(4'-nitrophenyl)-1,3-dioxolanes 1, 7-nitro-1,3-benzodioxane 2 and 5-nitro-1,3-benzodioxanes 3 was studied in aprotic medium (DMF/Et4NClO4 (0.1 M)). The voltammetric behavior o f these compounds showed the formation of a radical anion which is rel atively stable on the time scale of cyclic voltammetry. When the elect roreduction of these compounds was carried out at ca. -1.5 V vs Ag/Ag (0.01 M), at the potential of the formation of the radical anion, its cleavage did occur with the formation of the corresponding ketone. We also investigated the electroreduction of the 4-halomethyl- and 4,5-d ihalomethyl-1,3-dioxolanes (4 and 5). (C) 1997 Elsevier Science Ltd.