Enantioselective total synthesis of (−)-strychnine: development of a highly practical catalytic asymmetric carbon–carbon bond formation and domino cyclization
An enantioselective totalsynthesis of (−)-strychnine was accomplished through the use of the highly practical catalyticasymmetricMichaelreaction (0.1 mol% of (R)-ALB, greater than kilogram scale, without chromatography, 91% yield and >99% ee), and a domino cyclization that simultaneously constructed the B- and D- rings of strychnine (>77% yield). Newly-developed reaction conditions for thionium