PHOSPHONIUM YLIDE-CATALYZED CYCLOTRIMERIZATION OF ETHYL PROPYNOATE
摘要:
The cyclotrimerization of ethyl propynoate (2) to yield aromatic triesters is shown to proceed via consecutive [2+2] cycloadditions of ethoxycarbonylmethylenetriphenylphosphonium ylide (1) to three moles of (2), followed by cyclization and elimination of (1).