1,3-Dioxolane Formation by Nucleophilic Attack of Diazoalkanes on the Peroxide Bond of 1,2-Dioxetanes

Article abstract of DOI:10.1021/jo00083a027

The reaction of the 1,2-dioxetanes 1a-d with the diazoalkanes 2α-η was investigated.The two 3,3-disubstituted (3,3-dimethyl- and 3-(bromomethyl)-3-phenyl) dioxetanes (1a and 1b), trimethyldioxetane (1c) and tetramethyldioxetane (1d) gave with the various diazoalkanes 2 the corresponding 1,3-dioxolanes 3 (insertion products) and/or the dioxetane-derived ketone 4 (fragmentation).Nucleophilic attack by the negatively charged carbon pole of the diazoalkane on the sterically less hindered site of the dioxetane peroxide bond affords the 1,3-dioxolane 3 after cyclization with denitrogenation of the resulting O,N dipole.The O,C dipole, formed by the nucleophilic attack of the negatively charged nitrogen pole on the dioxetane, is proposed as precursor to the ketones 4 through Grob-type fragmentation with regeneration of the diazoalkane.