A-Aminoenone

Arnould, J.C., Cossy, J., and Pete, J.P. (1980) Reactivite photochimique des a-aminoenones reactions de cyclisation et nouveau type de reaction dans les a-Sulfonamido-cydohexenones. Tetrahedron, 36, 1585—1592. 

Four years after the isolation of cephalostatin A, the first synthetic studies in this area were reported. Fuchs etal. (38) reported the conversion of steroidal a-azidoketones 48 to the C-2 symmetrical nonacyclic and trisdecacyclic pyrazines 49 through catalytic reduction (Scheme 1). In the process they also observed an unusual azide-mediated formation of an unsymmetrical heterobenzyl azide (Scheme 2). Use of excess azide served as a base to generate the a-aminoenone 50. Dimerization of 50, followed by SN2 reaction with the hydrazoic acid coproduct yielded the unsymmetrical azidopyra-zine 51. 

In a further demonstration of this strategy, a convergent synthesis of the alkaloid hexahydroapoerysopine (94) was also achieved by Tu and coworkers (2010JOC5289). As shown in Scheme 22, treatment of enone 90 with sodium azide in DMF at 60 °C afforded a-aminoenone 92 in 47%... 

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