| 摘要 |
NEW MATERIAL:A polyprenyl-beta-hydroxycarboxylic acid expressed by formula I (formula II is trans-form isoprene unit; formula III is cis-form isoprene unit; n is an integer 11-19; R<1> is H or lower alkyl) or an ester thereof. USE:Useful as a raw material for medicines, cosmetics, etc., particularly as a synthetic raw material for dolichol playing a useful role in maintenance of mammal life. PREPARATION:A polyprenyl halide expressed by formula IV (X is halogen) is reacted with an acetoacetic acid ester expressed by formula V (R<2> is lower alkyl) in the presence of a basic compound to give a polyprenylketocarboxylic acid ester expressed by formula VI, which is then saponified to afford a polyprenylketocarboxylic acid expressed by formula VII. Only the carbonyl group at the beta-position of the resultant compound expressed by formula VII is selectively reduced to give the compound expressed by formula I (R<1> is H).
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