Polycyclopentanoids synthesis

Singh, V.K., Deota, RT., and Bedekar, A.V., Studies in the synthesis of polycyclopentanoids synthesis, oxa-di-7i-methane rearrangement of annulated bicyclo[2.2.2]octenones and cyclopropane ring cleavage of tetracyclo[6.3.0.0. > 0 > ]undecenones,/. Chem. Soc., Perkin Trans. 1, 903,1992. 

Bicyclo[2.2.2]octen-2-ones 25 afford tricyclo[3.3.0.0 ]octan-3-ones 26 in very good to excellent yields. Quantum yields for these conversions are in the range 0.5-1.0. The products have been used as building blocks in the synthesis of polycyclopentanoid terpenes and prostacyclin ana-logues. 2" - "... 

A full report has been published on the chemistry of the highly functionalized bicyclo[3.2.0]heptene (90), reaction of which with diazoethane gives a mixture ica. 7 3) of the useful ring-expanded products (91) and (92). A synthesis of another potential precursor (93) of polycyclopentanoids has also been reported. ... 

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