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US 6,403,838 B1Granted
Process for preparing 2,7-dimethyl-2,4,6-octatriene-1,8-dial
AssigneeSangho Koo
InventorsSangho Koo, Hojin Choi, Minsoo Park, Minkoo Ji
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Abstract
A process for making 2,7-dimethyl-2,4,6-octatrien-1,8-dial starting form an allylic halide is described. The process steps include aldehyde protection, conversion to a sulfide, oxidation to an allylic sulfone followed by a Ramberg-Backlund reaction and hydrolysis.
Claims2
A process for preparing 2,7-dimethyl-2,4,6-octatiene-1,8-dial, represented by Formula 2
- which comprises the steps of:
- (a) providing an allylic halide of Formula (A)
- wherein X is chosen from Br, Cl and I;
- (b) protecting the aldehyde of the allylic halide to obtain an acetal of Formula G
- wherein R3 and R4 are independently chosen from —H and —CH3;
- (c) reacting the acetal of step (b) with sodium sulfide to obtain di(3-formyl-3-methyl-2-propenyl)sulfide, dialkyl diacetal of Formula H;
- (d) oxidizing the product of step (c) to obtain an allylic sulfone of Formula I;
- (e) subjecting the allylic sulfone of step (d) to a Ramberg-Bäcklund reaction to obtain a triene of Formula J;
- (f) hydrolyzing the triene of step (e) to obtain a compound of Formula 2.
6 more elements
Dependencies are inferred from the claim text.