Process for preparing carotenoid polyene chain compounds and intermediates for preparing the same

A process for preparing an allylic sulfide of Chemical Formula 1, which comprises the steps of (a-1) oxidizing isoprene to obtain isoprene monoxide;

• (b-1) reacting the isoprene monoxide with benzenethiol to obtain 4-hydroxy-3-methyl-2-butenyl phenyl sulfide (A);
• and (c-1) reacting the compound (A) with a halogenating compound or sulfonylating compound.
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• In the formulas, X is selected from the group consisting of —Cl, —Br, —I, —OSO2CF3, —OSO2Ph, —OSO2C6H4CH3 and —OSO2CH3, and Ph represents phenyl group.

A process for preparing a carotenoid polyene chain compound represented by Chemical formula 2, which comprises the steps of (a-3) deprotonating the allylic disulfone compound (D), and reacting the resultant compound with not more than 0.5 equivalent of diallylic sulfide (E) (wherein, Y is a halogen atom) on the basis of 1 equivalent of allylic disulfone compound (D) to obtain allylic sulfide compound (F);

• (b-3) selectively oxidizing the allylic sulfide compound (F) to obtain allylic sulfone compound (G);
• (c-3) subjecting the allylic sulfone compound (G) to Ramberg-Bäklund reaction to give tetra(phenylsulfonyl)-triene compound (H);
• and (d-3) reacting the compound (H) with a base.
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• In the formulas, R is selected from the group consisting of hydrogen, C1˜C30 alkyl group, C1˜C30 alkenyl group, aryl group, —CN, —COOR′ (wherein, R′ is C1˜C10 alkyl group) and —C(═O)H, Y is selected from the group consisting of —Cl, —Br, —I, —OSO2CF3 —OSO2Ph, —OSO2C6H4CH3 and —OSO2CH3, and Ph represents phenyl group.