METHOD FOR PREPARING RETINAL OR ADDUCT (COMPLETE-E)-RETINAL WITH HYDROQUINONE AND INTERMEDIATE SUBSTANCES Russian patent published in 2008 - IPC C07C403/08 C07C403/10 C07C403/14 

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of retinal of the formula (I): being possibly in form of its adduct (complete-E)-retinal with hydroquinone. Method involves interaction of derivatives of 5-(2,6,6-trimethylcyclohex-1-enyl)-1,4-pentadiene or derivative of 5-(2,6,6-trimethylcyclohex-2-enyl)-1,4-pentadiene, or derivative of 5-(2,6,6-trimethyl-2-cyclohexene-1-ylidene)-1-pentene, or derivative of 5-(2,6,6-trimethylcyclohex-1-enyl)penta-1-ene-4-ine, or derivative of 5-(2,6,6-trimethylcyclohex-2-enyl)penta-1-ene-4-ine with derivative of 1,3-butadiene in the presence of Lewis of Brensted acid. Synthesized compound is subjected for treatment with a base or acid in solvent medium in order to eliminate R²H group, followed by if necessary hydrogenation and isomerization under basic or acidic conditions, or in the presence of metallic catalyst to the desired retinal of the formula (I). Retinal synthesized as a mixture of (9E/Z, 13E/Z)-isomers is isomerized if necessary to (complete -E)-retinal by formation of adduct of (complete-E)-retinal with hydroquinone. Also, invention relates to novel derivatives of 5-substituted pent(adi)ene(ine) used as intermediate compounds.

EFFECT: improved method of synthesis.

13 cl, 19 ex