2-[(E)-5-(3,4-Dimethoxy-phenyl)-1,4-dimethyl-pent-4-enyl]-4,5-dimethoxy-phenol 在
tetrabutylammonium tetrafluoroborate 作用下,
以
乙酸酐 为溶剂,
以69%的产率得到(1R,3aR,4S,9aR)-4-(3,4-Dimethoxy-phenyl)-8-methoxy-1,3a-dimethyl-2,3,3a,4-tetrahydro-1H-benzo[b]cyclopenta[c]furan-7-one