Synthesis of Monomorin I, a Trail Pheromone of the Pharao Ant (Monomorium pharaonis)

Article abstract of DOI:10.1002/hlca.19910740221

Catalytic hydrogenation of the 4-nitroalkanone 5 yielded the cis-pyrrolidine ester 6 (Scheme).The preparation of 5 was accomplished by ethanolysis of the nitrocyclohexanone derivative 4.Iodination at C(α) of 6, followed by cyclization, gave a nearly 5:6 mixture of the two C(5)-epimers 10/9 of octahydroindolizine.Epimerisation of the undesired 10 to 9 and subsequent transformation of the latter gave racemic monomorine I (1; 34percent yield from 5).