Ultrasound-Promoted Sodium Borohydride Reduction ofPentacyclo(5.4.0.0(2,6).0(3,10).0(5,9))Undecane-8,11-Dione (PCUD-8,11-Dione) and of 4,4-Dimethoxy-2,3,5,6-Tetrachloro-PCUD-8,11-Dione

摘要

Ultrasound-promoted reduction of pentacyclo(5.4.0.02,6.03,10.05,9) undecane-8,11-dione (i.e., PCUD-8,11-dione) with NaBH4 in the absence of added CeC13 affords a mixture of the corresponding endo, endo and exo, endo cage diols (67% and 30% yield, respectively). The corresponding reduction of PCUD-8,11-dione, when performed by using NaBH4 in the presence of added CeC13, affords isomerically pure endo, endo cage diol in 98% yield. Sonication promotes smooth reduction of the ketone carbonyl groups in 4,4-dimethoxy-2,3,5,6-tetrachloro-PCUD-8,11-dione by NaBH4-EtOH in the absence of CeCl 3. The exclusive product of this reduction is the corresponding exo,endo-8,11 -diol, which is produced in 90% yield. Ultrasound-promoted Reduction, Pentacyclic Cage Diketone, Sodium Borohydride, Endo,endo and exo,endo cage diols, Cerous Chloride,