Atropdiastereoselective Ring Opening of Bridged, “Axial‐Prostereogenic” Biaryls: Directed Synthesis of (+)‐Ancistrocladisine

Selective twisting of lactone 1 which has a flat, “axial prostereogenic” biaryl unit to the axial stereogenic ester 2 has been accomplished by a ring-opening reaction involving simple O-nucleophiles. This novel principle was the key to an atropisomer-selective synthesis of the lianene alkaloid ancistrocladisine.