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Trennung und absolute Konfiguration der C(8)-epimeren (all-E)-Neochrome (Trollichrome) und -Dinochrome

✍ Scribed by Edith Märki-Fischer; Richard Buchecker; Conrad Hans Eugster


Publisher
John Wiley and Sons
Year
1984
Tongue
German
Weight
296 KB
Volume
67
Category
Article
ISSN
0018-019X

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✦ Synopsis


Separation and Absolute Configuration of the C(8)‐Epimeric (app‐E)‐Neochromes (Trollichromes) and ‐Dinochromes

The C(8′)‐epimers of (all‐E)‐neochrome were separated by HPLC and carefully characterized. The faster eluted isomer, m.p. 197.8–198.3°, is shown to have structure 3 ((3__S__,5__R__,6__R__,3′S,5′R,8′R)‐5′,8′‐epoxy‐6,7‐dodehydro‐5,6,5′,8′‐tetrahydro‐β,β‐carotene‐3,5,3′‐triol). To the other isomer, m.p. 195‐195.5°, we assign structure 6, ((3__S__,5__R__,6__R__,3′S,5′R,8′R)‐5′,8′‐epoxy‐6,7‐didehydro‐5,6,5′,8′‐tetrahydro‐β,β‐carotene‐3,5,3′‐triol). The already known epimeric dinochromes (= 3‐O‐acetylneochromes) can now be formulated as 4 and 5, (‘epimer 1’ and its trimethylsilyl ether) and 7 and 8, (‘epimer 2’ and its trimethylsilyl ether), respectively.