Abstract
(±)-Nitramine (la) was synthesized in seven steps from methylenecyclohexane in 33% overall yield. A three-step sequence was developed from methylenecyclohexane to aldehyde 4 in which methyl -chloroacrylate was used as a ketene equivalent in the ene reaction. Aldehyde 4 was converted to nitrone 3 which cyclized to a 2.5:1 mixture
of 2 and 9. Hydrogenolysis of 2 gave la. Lewis acid catalyzed cyclization of 4 gave a 3.5:1 mixture of hydrindanones 13and14at25°Canda 12:1mixtureof13and14at-20°C.