54200-90-7

Upstream product

• 33398-38-8 2-Methyl-3-ethoxycarbonyl-2-propenyltriphenylphosphonium Bromide 
• 34341-28-1 2,3,4-trimethylbenzaldehyde 
• 115376-74-4 5-(2,3,4-trimethylphenyl)-3-methyl-2,4-pentadienoic acid 

Downstream Products

• 54244-21-2 12'-apo-χ-caroten-12'-al 
• 54200-91-8 3-methyl-5-(2,3,4-trimethylphenyl)penta-2,4-dien-1-yltriphenylphosphonium bromide 

Relevant academic research and scientific papers

Animal carotenoids. 31. Structure elucidation of a sponge metabolite via mesylate elimination.

The structure of a sponge metabolite from Microciona prolifera, previously considered to be (6S)-2,3-didehydro- or 3,4-didehydro-gamma, chi-carotene, has been further studied. Attempted total synthesis of the 3,4-didehydro derivative provided the hitherto unknown gamma, chi-carotene, the synthesis of which is described. Hydrolysis of lutein methanesulfonate diester (dimesylate) gave elimination products possessing the 3,4-didehydro gamma end-group. 1H NMR data for this gamma end-group were identical with those for the sponge carotenoid. The mesylate elimination reaction described may mimic the metabolic formation of the 3,4-didehydro-gamma-carotenoid end-group. In connection with other investigations on functionalized carotenoids we further report the preparation of zeaxanthin and lutein mesylates and their base-catalyzed elimination reactions. SN2 type substitution reactions of zeaxanthin dimesylate with appropriate nucleophiles did not produce beta, beta-carotene, zeaxanthin diacetate or thiozeaxanthin.