A novel, stereoselective synthesis of cis-4a(S), 8a(R)-decahydro-6(2H)-isoquinolones from meroquinene esters

Article abstract of DOI:10.1016/S0040-4039(00)73922-0

Intramolecular cyclization of N-acylated meroquinene t-butyl esters in cold H₂SO₄ cleanly afforded cis-4a(S), 8a(R)-decahydro-6(2H)-isoquinolones with complete stereocontrol in >95% yield. Formation of the meroquinene esters from cinchona alkaloid autoxidation using an improved Doering protocol was accomplished in three steps with 85% overall yield.