| abstract |
PURPOSE: To obtain an optically active ketone useful as an alarm pheromone of ant, etc., in high yield, by carrying out the pinacol rearrangement of an optically active sulfonyloxy alcohol in a solvent using a compound such as diethyl aluminum chloride as a reaction accelerator. n CONSTITUTION: The optically active ketone of formula III [e.g. (S)-6-methyl-5- decanone] can be produced by the rearrangement reaction of an optically active sulfonyloxy alcohol of formula I (R 1 WR 3 are 1W20C hydrocarbon group which may contain N, O, P or S; the carbon marked with * is asymmetric) [e.g. (S)-3- butyl-2-methanesulfonyloxy-3-heptanol] in the presence of an organic aluminum compound of formula II (R 4 is 1W20C alkyl; X is halogen, alkoxy or CN; n is 1, 1.5 or 2) in a solvent such as methylene chloride, toluene, xylene, etc., preferably at room temperature W -80°C. n EFFECT: The reaction proceeds under mild condition without causing racemization of the product. n COPYRIGHT: (C)1985,JPO&Japio |