Efficient Syntheses of the OPC Homologous Series, OPC-1:0, -3:0, -4:0, -5:0, -6:0, -7:0, and-8:0.

The OPC homologous series was synthesized from 2-[(Z)-2-pentenyl]cyclopenten-1-one in short steps and with high yields. The carbon-carbon bond information was achieved by the 1,4-conjugate addition approach. This method makes it possible to supply a sufficient amount of OPC homologues which would enable significant information to be collected for plant physiological studies.