ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Synthesis of Optically Active Natural Carotenoids and Structurally Related Compounds. X. Synthesis of (3R,3′S,5′R)-Capsanthin, (3S,5R,3′S,5′R)-Capsorubin, (3′S,5′R)-Cryptocapsin, and Some Related Compounds. A New Approach to Optically Active, Five-Membered-Ring Carotenoid Building Units by HydroboratonThe synthesis of (3R,3′S,5′R)-capsanthin (1), (3S,5R,3′S,5′R)-capsorubin (2), and (3′S,5′R)-cryptocapsin (3), found in the red paprika Capsicum annuum, is described using (+)-camphor (7) as a readily available starting material. As the key reaction, the unsaturated acetal 16 is hydroborated with (+)-diisopinocampheylborane to give the hydroxy ketone 12a in very high chemical and optical yield. A subsequent aldol condensation with 13 in THF/toluene gives 2 in high yield. The C40-compounds 1 and 3 are synthesized using the same type of condensation. The pigments 1-3 are transformed by an Oppenauer oxidation to (3R,5′R)-capsanthone (5), (5R,5′R)-capsorubone (4) and (5′R)-cryptocapsone (6), respectively.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19830660706
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