92760-20-8

Basic information

• Product Name: (3R,6'R)-3-hydroxy-3',4'-didehydro-β,γ-carotene
• Synonyms: (3R,6'R)-3-hydroxy-3',4'-didehydro-β,γ-carotene
• CAS NO: 92760-20-8
• Molecular Weight: 550.868
• Mol File: 92760-20-8.mol
• Article Data: 5

Chemical Properties

• CAS DataBase Reference: (3R,6'R)-3-hydroxy-3',4'-didehydro-β,γ-carotene(CAS DataBase Reference)
• NIST Chemistry Reference: (3R,6'R)-3-hydroxy-3',4'-didehydro-β,γ-carotene(92760-20-8)
• EPA Substance Registry System: (3R,6'R)-3-hydroxy-3',4'-didehydro-β,γ-carotene(92760-20-8)

Safety Data

• Hazardous Substances Data: 92760-20-8(Hazardous Substances Data)

Upstream product

• 127-40-2 lutein 
• 851854-29-0 (3R,3'R,6'R)-lutein 3'-propyl ether 
• 144-68-3 zeaxanthin 

Downstream Products

• 54422-80-9 (3R)-3-hydroxy-3',4'-didehydro-β,β-carotene 
• 144-68-3 zeaxanthin 
• 472-70-8 (3R)-cryptoxanthin 
• 24480-38-4 zeinoxanthin 

Relevant articles and documents

Process For The Preparation of Beta and Alpha Cryptoxanthin

The present invention relates to a process for converting lutein and/or lutein esters to (3R)-β-cryptoxanthin and (3R,6′R)-α-cryptoxanthin, suitable for human consumption as dietary supplements, by employing safe and environmentally friendly reagents. (3R)-β-Cryptoxanthin and (3R,6′R)-α-cryptoxanthin are two rare food carotenoids that are not commercially available and the former exhibits vitamin A activity. In the first synthetic step, commercially available lutein and/or lutein esters are transformed into a mixture of dehydration products of lutein (anhydroluteins) in the presence of a catalytic amount of an acid. The resulting anhydroluteins are then converted to (3R)-β-cryptoxanthin (major product) and (3R,6′R)-α-cryptoxanthin (minor product) by heterogeneous catalytic hydrogenation employing transition elements of group VIII (Pt, Pd, Rh supported on alumina or carbon) in a variety of organic solvents under atmospheric pressure of hydrogen and at temperatures ranging from ?15° C. to 40° C. Among these catalysts, Pt supported on alumina at 40° C. in ethyl acetate provides the best yield of (3R)-β-cryptoxanthin and (3R,6′R)-α-cryptoxanthin. Several homogeneous catalysts can also promote the regioselective hydrogenation of anhydroluteins to a mixture of (3R)-β-cryptoxanthin and (3R,6′R)-α-cryptoxanthin in low to moderate yields. The catalysts may be transition metal complexes such as palladium acetylacetonate, Rh(Ph3P)3Cl (Wilkinson's catalyst), [(C6H11)3P[C8H12][C5H5N] Ir+PF6? (Crabtree catalyst), or [C8H12][(MePh2P)2]Ir+PF6?. Among these, Wilkinson catalyst converts anhydroluteins to (3R)-β-cryptoxanthin and (3R,6′R)-α-cryptoxanthin in nearly quantitative yield. A novel feature of this invention is the regioselective hydrogenation of anhydroluteins while the highly conjugated polyene chain of these carotenoids remains intact.

Confirmation of the absolute (3R,3′S,6′R)-configuration of (all-E)-3′-epilutein

Circular dichroism (CD) spectroscopy was used to distinguish between the isomeric (all-E)-configured 3′-epilutein (2) and 6′-epilutein (8) to establish the absolute configuration of epilutein samples of different (natural and semisynthetic) origin, including samples of 2 obtained from thermally processed sorrel. Thus, the CD data of lutein (1) and epilutein samples (2) were compared. Our results unambiguously confirmed the (3R,3′S,6′R)- configuration of all epilutein samples. Compound 2 was thoroughly characterized, and its 13C-NMR data are published herewith for the first time.

Absolute configuration of xanthophyll (lutein)

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