Process for making 4,4'-diketo-carotenoids
AssigneeRoche Vitamins Inc.
InventorsBruno Burdet, August Ruttimann
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Abstract
A process for the manufacture of a symmetrical, terminally ring-substituted polyenes by reacting a polyene di(O,O-dialkyl acetal) with a cyclic dienol ether in the presence of a Lewis or Brönsted acid, hydrolyzing the condensation product resulting therefrom and cleaving off alcohol under basic or acidic conditions from the polyene derivative produced at this stage. The novel cyclic dienol ethers, as well as, novel intermediates resulting from the condensation and additional intermediates in this process form further aspects of the invention. The final products are primarily carotenoids, which find corresponding use, e.g., as colorings and pigments for foodstuffs, animal products, etc.
Claims41
A process for the manufacture of a symmetrical, terminally ring-substituted polyenes of formula I 18
- wherein
- R1 is hydrogen or hydroxy;
- m is 0 or 1;and
- n is 0, 1, or 2,
- the process comprising
- (a) reacting a polyene di(O,O-dialkyl acetal) of formula II 19
- wherein
- R2 is C1-6-alkyl and
- n is 0, 1, or 2,
- with a cyclic dienol ether of formula III 20
- wherein
- R3 is hydrogen;
- R4 is C1-4-alkoxy;
- or
- R3 and R4 together form an optionally substituted methylenedioxy group, —O—C(R5)(R6)—O—, wherein R5 and R6 are each independently hydrogen, C1-4-alkyl, or phenyl, and
- m is 0 or 1;
- in the presence of a Lewis or Brönsted acid,
- (b) hydrolyzing the reaction product under acidic conditions;
- and
- (c) cleaving off the alkanol R2 OH from the thus-obtained compound of formula IV 21
- wherein
- R1 is hydrogen or hydroxy depending on whether R3 and R4 in formula III are hydrogen and C1-4-alkoxy, respectively, or R3 and R4 together form the optionally substituted methylenedioxy group, and
- R2, m and n are as previously defined in this claim,
- under basic or acidic conditions.
A compound of formula III 22
- wherein
- R3 is hydrogen and
- R4 is C1-4-alkoxy or
- R3 and R4 together form an optionally substituted methylenedioxy group —O—C(R5)(R6)—O—, wherein R5 and R6 are each independently hydrogen, C14-alkyl, or phenyl, and
- m is 0 or 1.
A compound of formula IV 23
- wherein
- R1 is hydrogen or hydroxy;
- R2 is C1-6-alkyl;
- m is 0 or 1;
- and
- n is 0, 1, or 2.
A compound of formula V 24
- wherein
- R1 is C1-6-alkyl;
- R4 is C1-4-alkoxy,
- m is 0 or 1;
- and
- n is 0, 1, or 2.
A compound of formula VI 25
- wherein
- R2 is C1-6-alkyl;
- R5 and R6 are each independently hydrogen, C1-4-alkyl, or phenyl;
- m is 0 or 1;
- and
- n is 0, 1, or 2.
Dependencies are inferred from the claim text.