Chemistry of adamantane. Part IX. 1,2-Difunctional adamantanes; synthesis and reactions of protoadamantane-4-spiro-oxiran

Abstract

The synthesis of protoadamantane-4-spiro-oxiran {octahydrospiro[2,5-methano-1H-indene-7,2′-oxiran]} and its isomerisation to protoadamantane-4-carbaldehyde are described. Electrophilic cleavage of the oxiran ring with simultaneous rearrangement gives 1,2-difunctional adamantane derivatives. Reactions of lithium carbenoids, from benzylidyne chloride and benzylidene bromide, with protoadamantan-4-one mainly lead to protoadamantan-4-yl phenyl ketone. 4-Phenylprotoadamantan-4-ols on treatment with acid preferentially undergo elimination to give 4-phenylprotoadamantene.