| 摘要 |
Compounds of formula (I) wherein Ar is selected from the group consisting of phenyl, diphenyl, naphthyl, thienyl and pyrrolyl which groups may be substituted by a substituent selected from the group consisting of halogen atoms, C1-C4-alkyl, C3-C6-cycloalkyl, benzyl, hydroxy, C1-C4-alkoxy, C1-C4-alkylthio, C1-C4-haloalkyl, C1-C4-haloalkoxy, phenoxy, thienylcarbonyl and benzoyl, R repreents a C1-C4 alkyl; R1 and R2, which may be the same or different, represent a hydroxy, an O-M+, an OR3 or an group, R3 represents a C1-C24 alkyl, a C3-C6 cycloalkyl, a phenyl or a benzyl group; M+ represents the cation of an alkaline metal; R4 and R5, equal to or different from each other, represent a hydrogen atom, a C1-C4 alkyl, a C5-C6 cycloalkyl, a (CH2)n-CH2OH group with n=1, 2 or 3, or R4 and R5 together form a group (CH2)m with m=4 or 5; a group -CH2-CH2-R6-CH2-CH2- in which R6 is an oxygen atom, an N-H or N (C1-C4) alkyl group; X represents a hydroxy, aacetoxy, trifluoroacetoxy, trichloroacetoxy, benzoyloxy, 4-nitrobenzoyloxy, mesyloxy, benzensulphonyloxy or tosyloxy group, the carbon atoms marked by an asterisk being both contemporaneously in the R or S configuration. The preparation of the compound of formula I by ketalization or by trans-ketalization with tartaric acid derivatives and their rearrangement into alpha-arylalkanoic acids is described too. |
