abstract |
Multiple novel reaction schemes, novel process steps and novel intermediates are provided for the synthesis of epoxymexrenone and other compounds of Formula I wherein: -A-A- represents the group -CHR<SUP>4</SUP>-CHR<SUP>5</SUP>- or CR<SUP>4</SUP>-CR<SUP>5</SUP>- R<SUP>3</SUP>, R<SUP>4 </SUP>and R<SUP>5 </SUP>are independently selected from the group consisting of hydrogen, halo, hydroxy, lower alkyl, lower alkoxy, hydroxyalkyl, alkoxyalkyl, hydroxycarbonyl, cyano, aryloxy, R<SUP>1 </SUP>represents an alpha-oriented lower alkoxycarbonyl or hydroxyalkyl radical, -B-B- represents the group -CHR<SUP>6</SUP>-CHR<SUP>7</SUP>- or an alpha- or beta-oriented group: where R<SUP>6 </SUP>and R<SUP>7 </SUP>are independently selected from the group consisting of hydrogen, halo, lower alkoxy, acyl, hydroxyalkyl, alkoxyalkyl, hydroxycarbonyl, alkyl, alkoxycarbonyl, acyloxyalkyl, cyano, aryloxy, and R<SUP>8 </SUP>and R<SUP>9 </SUP>are independently selected from the group consisting of hydrogen, halo, lower alkoxy, acyl, hydroxyalkyl, alkoxyalkyl, hydroxycarbonyl, alkyl, alkoxycarbonyl, acyloxyalkyl, cyano, aryloxy, or R<SUP>8 </SUP>and R<SUP>9 </SUP>together comprise a carbocyclic or heterocyclic ring structure, or R<SUP>8 </SUP>or R<SUP>9 </SUP>together with R<SUP>6 </SUP>or R<SUP>7 </SUP>comprise a carbocyclic or heterocyclic ring structure fused to the pentacyclic D ring. |