Reduction by dissolving metals. XV. Reactions of some cyclohexadienes with metal-ammonia solutions

Reduction by metal-ammonia solutions of 1-methoxycyclohexa-1,3-dienes gives mixtures of cyclohexenes and 1-methoxycyclohexenes, the ratios being de- pendent on presence or absence of an alcohol. In the absence of a proton source other than ammonia 1-methoxycyclohexa-1,4-dienes are reducible directly, under- going preliminary conjugation under the basic conditions. Possible mechanisms are discussed.