132274-12-5

Upstream product

• 132340-89-7 (2E,4E)-5-((1R,4R)-1,4-Dihydroxy-2,6,6-trimethyl-cyclohex-2-enyl)-3-methyl-penta-2,4-dienoic acid methyl ester 
• 30816-18-3 (2E,4E)-5-((R)-1-Hydroxy-2,6,6-trimethyl-4-oxo-cyclohex-2-enyl)-3-methyl-penta-2,4-dienoic acid methyl ester 
• 122346-85-4 C₁₂H₁₈O₄ 
• 132340-90-0 (2E,4E)-5-((1R,2R,5R,6R)-2,5-Dihydroxy-1,3,3-trimethyl-7-oxa-bicyclo[4.1.0]hept-2-yl)-3-methyl-penta-2,4-dienoic acid methyl ester 
• 98-59-9 p-toluenesulfonyl chloride 

Relevant academic research and scientific papers

Carotenoids with 7-Oxabicycloheptyl End Groups. Attempted Synthesis of Cycloviolaxanthin (=(3S,5R,6R,3'S,5'R,6'R)-3,6:3',6'-Diepoxy-5,6,5'6'-tetrahydro-β,β-carotin-5,5'-diol)

Starting from our recently described synthon (+)-24, the enantiomerically pure 3,6:4,5:3',6':4',5'-tetraepoxy-4,5,4',5'-tetrahydro-ε,ε-carotene (34) and its 15,15'-didehydro analogue 32 were synthesized in eleven and nine steps, respectively (Scheme 4).Chiroptical data show, in contrast to the parent ε,ε-carotene, a very weak interaction between the chiral centers at C(5), C(5'), C(6), C(6'), and the polyene system.Diisobutylaluminium hydride reduction of 32 lead rather than to the expected 15,15'-didehydro analogue 35 of cycloviolaxanthin (8), to the polyenyne 36 (Scheme 5).We explain this reaction by an oxirane rearrangement leading to a cyclopropyl ether followed by a fragmentation to an aldehyd on the one side and an enol ether on the other (Scheme 6).This complex rearrangement includes a shift of the whole polyenyne chain from C(6), C(6') to C(5), C(5') of the original molecule.