Enantioselective syntheses of diquinane and (cis, anti, cis)-linear triquinanes

The enantioselective syntheses of diquinane and cis, anti, cis-linear triquinanes, starting from the readily available (S)-campholenaldehyde, employing an intramolecular rhodium carbenoid CH insertion reaction, are described.

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(1S,3S)-3-(2-Methoxyethyl)-2,2-dimethylcyclopentane-1-carboxylic acidC11H20O3[α]D26=-5.2 (c 2.0, CHCl3).Source of chirality: campholenaldehydeAbsolute configuration: (1S,3S)

(1S,5R,6S)-6-(2-Methoxyethyl)-5-methylbicyclo[3.3.0]octan-2-oneC12H20O2[α]D21=+1.4 (c 13.3, CHCl3).Source of chirality: campholenaldehydeAbsolute configuration: (1S,5R,6S)

(1R,3R,5S,7R)-7-Methoxy-2,2-dimethylbicyclo[3.3.0]octane-3-carboxaldehydeC12H20O2[α]D21=-21.2 (c 9.8, CHCl3).Source of chirality: campholenaldehydeAbsolute configuration: (1R,3R,5S,7R)

(1R,2S,6R,8S,10R)-10-Methoxy-2-methyltricyclo[6.3.0.02,6]-undecan-5-oneC13H20O2[α]D25=-45.5 (c 1.6, CHCl3).Source of chirality: campholenaldehydeAbsolute configuration: (1R,2S,6R,8S,10R)