| 摘要 |
In prodn. of opt; p-alkyl-substd.3-phenyl-2-methyl -propanol derivs. of formula (I), a methallyl-benzene deriv. (IIa) or its mixt. with the corresp. isobutenyl-benzene (IIb) is subjected to peroxide-catalysed addition of HBr; the resulting bromo cpd. (IIIa) or (IIIb) is reacted with a carboxylic acid alkali salt (to which an acid and/or a polar solvent are optionally added) at 100-200 deg.C or at up to reflux temp., the molar ratio of bromo cpd. to alkali salt being up to 1:10; and the resulting ester (IV) is hydrolysed or trans-esterified with a low-boiling alcohol. (In the formulae, R1 = H, CH3, C2H5, isopropyl or tert-butyl; R1 being in the p-position andopt. accompanied by positional isomers; R2 = H, CH3, C2H5, n-propyl or isopropyl; M = alkali metal). HBr is pref. used in amt. stoichiometrically equivalent to all of the isomers of formulae (IIa) and (IIb) and the addition reaction is pref. carried out at 0-20 deg.C. The bromo cpd. (IIIa,b) is pref. reacted with a 1-4C carboxylic acid alkali salt, pref. CH3XOONa or CH3COOK, generally at 100-200 (pref. 120-180)deg.C, the molar ratio of bromo cpd. to alkali salt pref. being 1:1 or 1:2.
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