Reductive Studies on 3-Oxidopyrylium-alkene [5+2] Cycloadducts: Access to Some Hydroxy Cycloheptenoids

Abstract

[image omitted] The scope of nickel boride as a versatile reducing reagent is extended to the 3-oxidopyrylium-alkene [5+2] cycloadducts. In this report, we demonstrate that nickel boride is capable of one-pot 1,2- and 1,4-reduction of enones present in the cycloadducts in good yields. Subsequent elaboration of the cycloadducts towards synthesis of functionalized cycloheptenoid derivatives devoid of the oxa-bridge is also explored.