Preparation of unsaturated hydroperoxides from N-alkenyl-N′-p-tosylhydrazines

Abstract

Unsaturated hydroperoxides (R¹R²CHO₂H), 2-phenylpent-4-enyl hydroperoxide (1), 3-phenylhex-5-en-2-yl hydroperoxide (2), 5-methylhex-5-en-2-yl hydroperoxide (3), cyclo-oct-4-enyl hydroperoxide (18), and cyclo-oct-3-enyl hydroperoxide (24) have each been prepared from the corresponding carbonyl compound (R¹R²CO) by the sequence: i, conversion to the p-tosylhydrazone (R¹R²CN–NHTs); ii, reduction with sodium cyanoborohydride at pH 3.5 to give the N′-p-tosylhydrazine (R¹R²CH–NH–NHTs); and iii, oxidation with hydrogen peroxide and sodium peroxide, Isomerisation occurs in the preparation of the cyclo-octenyl hydroperoxides, particuarly if the pH falls markedly below 3.5 in the reduction step.