ALPHA-ALKOXY KETONES FROM THE NUCLEOPHILIC-SUBSTITUTION ON THE PEROXIDE BOND OF 3,3-DISUBSTITUTED 1,2-DIOXETANES BY ENAMINES

The reaction of 1,2-dioxetanes with enamines as pi-nucleophiles was investigated. 3,3-Dibenzyl-1,2-dioxetane (1) was allowed to react with enamines 2a-c in methylene chloride to afford after hydrolysis the corresponding alpha-alkoxylated ketones 4a-c. Additionally, the reaction of the dimedone-derived enamine 3 with dioxetane 1 yielded the oxidized enamine adduct 4. Nucleophilic attack of the enamine beta-carbon (S(N)2 reactivity) on the sterically less hindered site of the dioxetane peroxide bond is proposed to constitute the initial step of the reaction.