115376-82-4Relevant academic research and scientific papers
Animal carotenoids. 31. Structure elucidation of a sponge metabolite via mesylate elimination.
Sliwka,N?kleby,Liaaen-Jensen
, p. 245 - 252 (2007/10/02)
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.
Partial Syntheses of Diastereomeric Carotenols
Sliwka, Hans-Richard,Liaaen-Jensen, Synnoee
, p. 518 - 525 (2007/10/02)
The application of the Mitsunobu reaction was successfully tested on (3R,3'R)-zeaxanthin, giving the (3S,3'S)-enantiomer and meso form.Applied to natural (3R,3'R,6'R)-lutein, this inversion reaction allowed the preparation of the three other 6'R diastereomers. (3S,3'S,6'R)-lutein with 3',6'-cis-configuration of the ε-ring has not been synthesized before.The observed Cotton effects of the eight lutein diastereomers are rationalized by application of the additivity hypothesis.New trivial names are suggested for the eight lutein isomers on the basis of structural relationships.
