A new route to keto and alkyl derivatives of (R)-carvone via diastereoselective conjugate addition of nitronate ions

The reactivity and diastereoselectivity of conjugate addition of different nitronates ions to (R)-carvone was systematically studied. The Michael adducts 2a-e were obtained in good yield and 3,2-cis-3,5-trans selectivity. The nitroadducts 2b,c were transformed via Nef reaction into (R)-carvone ketone derivatives 9,10 and nitroadducts 2b,d led to (R)-carvone alkylated derivatives 11,12, via a denitration reaction.