Formal Syntheses\nof (−)-Quinocarcinamide and\n(−)-Quinocarcin

Concise and scalable formal syntheses of (−)-quinocarcinamide\nand (−)-quinocarcin have been achieved in 9 steps with 9% overall\nyield from simple commercially available chemicals. The synthetic\nstrategy features an <i>ortho</i>-regioselective Pictet–Spengler\ncyclization for the construction of the tetrahydroisoquinoline skeleton,\na stereoselective formal intramolecular [3 + 2] cross cycloaddition\nof cyclopropane 1,1-diester with an imine for the construction of\nthe 3,8-diazabicyclo[3.2.1]octane skeleton.