| 摘要 |
NEW MATERIAL:An alpha-hydroxycarboxylic acid shown by the formula I (R<1> is H, or lower alkyl; R<2> and R<3> are H, lower alkyl, lower alkoxy, or R<2> and R<3> are linked to form group shown by the formula II; R<4> is H, or protecting group; n is 0, 1, or 2), its ester, and a salt. EXAMPLE:2-Hydroxy-3-[2-(3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-b enzopyranyl)]propionic acid. USE:An antioxidant for organic materials such as fats and oils sensitive to oxygen, rubber products, plastic or processed foods, etc., more improved than vitamin E, and an intermediate for it. PREPARATION:An aldehyde shown by the formula III is reacted with a cyanide compound to give an alpha-hydroxynitrile shown by the formula IV, which is hydrolyzed to give easily a compound shown by the formula I . And, if necessary, this compound is esterified or subjected to salt formation reaction.
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