SYNTHESIS OF (+ -)-NITRAMINE AND (+/-)-ISONITRAMINE BY UTILIZING STEREOSELECTIVE REDUCTION OF ETHYL 1-(3-BROMOPROPYL)-2-OXOCYCLOHEXANECARBOXYLATE/

Formal synthesis of (+/-)-nitramine (1) and (+/-)-isonitramine (2) was achieved. Thus, the reduction of ethyl 1-(3-bromopropyl)-2-oxocyclohe xanecarboxylate (6) with NaBH4 in MeOH gave the corresponding cyclohex anol (7) having cis geometry between hydroxyl and ester groups, predom inantly. On the other hand, the trans located isomer (8) was preferent ially obtained by reduction with LiAl(OBu')(3)H in THF. Treatment of t he former reduction product (7) having cis geometry with benzylamine a t 60 degrees C gave cis located ethyl nzylamino)-propyl)-2-hydroxycycl ohexanecarboxylate (9), which was further treated with BuLi to give a spirolactam, 2-benzyl-7-hydroxy-2-azaspiro[5,5]undecan-1-one (11) in 8 4% yield. Reduction of the lactam (11) with BH3 . SMe2 in THF gave N-b enzylnitramine (13). In a similar manner, N-benzylisonitramine (14) wa s synthesized from trans located hydroxyaminoester (10).