New access to chiral pyrrolidine and piperidine β-enamino ketones. Application to the enantioselective synthesis of (–)-hygroline

We report here a new access to chiral pyrrolidine and piperidine β-enamino ketones by condensation of (S)-phenylglycinol with ω-oxo alkynones.As an illustration of the synthetic potential of the target compounds, the total enantioselective synthesis of alkaloid (-)-hygroline was achieved.