| 摘要 |
Novel acids and derivatives with terminal dioxo-ene structures are obtained by UV photooxygenation ring-opening of mono-substituted furans with singlet oxygen, followed by reduction. Aliphatic acids of formulae (I) and (II) having a conjugated dioxo-ene structure consisting of a carbonyl group, a terminal aldehyde function and between them, a Z- or E-double bond are new. Independent claims for also included for the following: (i) preparation of (I) and (II). (ii) derivatives of formula (IV) with R = OR1, obtained from (IV : R = OH) by esterification with R1OH; (iii) acids of formula (IV : R = OH), obtained from compounds of formula (III: R = OH) by acidic Clemmensen reduction with Zn/Hg/HCl or alkaline Woolf-Kishner reduction with KOH in a high-boiling solvent such as triethyleneglycol; (iv) acid derivatives of formula (IV: R = OR1) obtained from (III : R = OR1) by acidic Clemmensen reduction with Zn/Hg/HCl; (v) acids of formula (III) with R = OH, obtained by acidic or alkaline hydrolysis of (III : R = OR1); and (vi) derivatives of formula (III : R = OR1), obtained by acylation of furan with a diacid mono-ester mono-halide of formula (V) in an inert solvent in presence of a Lewis acid such as AlCl3, BF3 or SnCl4. R = OH or OR1; R1 = CmH2m+1, benzyl, phenyl, toluyl or xylyl; m = 1-5; n = 1-13, with the proviso that the case with n = 7 is excluded when R = OH; and X = Cl, Br or I.
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