SYNTHESIS OF MUSCOPYRIDINE AND ITS ANALOGS

Muscopyridine (1)is one of the odoriferous constituents of natural musk. 1 was prepared previously in very low yield in multisteps. We report here one-step preparation of muscopyridine and its analogs by the cross-coupling method. The cyclocoupling is effected by slow dropwise addition of a THF solution of di- Grignard reagent under nitrogen to a well stirred mixture of an equimolar quantity of a dichloropyridine in THF containing a catalytic amount of Ni (dppp)Cl₂. The reaction mixture is stirred at 35～40℃ for up to 20 h. Analogs 2,3 and 4 have also been prepared by this method. The structure of these products and intermediates are determined by UV, IR, MS, and ¹HNMR spectral data.