REACTION OF CERTAIN ALPHA,BETA-UNSATURATED TERPENIC OXIMES WITH SODIUM-NITRITE IN ACETIC-ACID - A FACILE SYNTHESIS OF ALLYLIC NITRO-COMPOUNDS

Reaction of nitrous acid with alpha,beta-unsaturated oximes having the structural fragment of 2-methyl-3-hydroxyimino-1-cyclohexene is descr ibed. A set of the oximes studied includes simple monocyclic derivativ es (2-methyl-2-cyclohexenone oxime and carvone oxime) as well as more complex bicyclic compounds (car-2-en-4-one oxime and a-muurolen-3-one oxime). The reaction was shown to give allylic nitro compounds either with the retention of the carbon frame or with the rearranged skeleton . Chemical structure and stereochemistry of the products obtained are established by H-1, C-13 and N-14 NMR spectroscopy together with IR an d UV data. Possible mechanisms of the reaction are discussed. Molecula r mechanics and MNDO-calculations are used for the mechanistic study.