Metathesis-Mediated Route to 6,6-Bicyclic Malonamides

Significance

A synthetic approach involving classical Grignard and modern metathesis chemistry affording 6,6-bicyclic malonamides (BMA) is presented. Starting with a double allyl Grignard addition to ethyl formate followed by base-mediated malonate alkylation affords the requisite meta­thesis precursor which, under Grubbs I catalytic conditions, leads to the expected cyclopentene. Pedagogically well-accepted strategy for the construction of acyclic functionalized derivatives by ozonolysis of cyclic olefins is then followed and leads to a diamine precursor which, upon reductive amination and hydrogenolysis, affords the BMA derivatives. The synthesis of 10 BMAs is ­described.