Stereospezifische Synthese von (+)‐(3R, 4R)‐4‐Methyl‐3‐heptanol, das Enantiomere eines Pheromons des kleinen Ulmensplintkäfers (Scolytus multistriatus)

Abstract

Stereospecific Synthesis of (+)‐(3R, 4R)‐4‐Methyl‐3‐heptanol, the Enantiomer of a Pheromone of the Smaller European Elm Bark Beetle (Scolytus multistriatus)Reduction of 2 with actively fermenting baker's yeast gave (−)‐3. Stereospecific alkylation [3] of (−)‐3 with propyl iodide furnished ethyl (+)‐(2R, 3R)‐2‐propyl‐3‐hydroxypentanoate ((+)‐4, 58%) which was converted to the tetrahydropyranyl ether (−)‐5, then the alcohol 6, the p‐toluenesulfonate 7 and the thiophenyl ether 8 to give the title compound (+)‐1. The latter consisted of 97% of the threo‐ and 3% of the erythro‐isomer. The above synthesis also correlates the absolute configuration of (−)‐(R)‐3 with that of (+)‐(R)‐citronellic acid (see [2]).