Synthesis of (-)-paroxetine via enantioselective phase-transfer catalytic monoalkylation of malonamide ester.

A new enantioselective synthetic method of (-)-paroxetine is reported. (-)-Paroxetine could be obtained in 15 steps (95% ee and 9.1% overall yield) from N,N-bis(p-methoxyphenyl)malonamide tert-butyl ester via the enantioselective phase-transfer catalytic alkylation and the diastereoselective Michael addition as the key steps.