Stereochemische Korrelationen zwischen (2R,4′R,8′R)-α-Tocopherol, (25S,26)-Dihydroxycholecalciferol, (–)-(1S,5R)-Frontalin und (–)-(R)-Linalol

✍ Scribed by Richard Barner; Josef Hübscher

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: German
• Weight: 678 KB
• Volume: 66
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19830660321

✦ Synopsis

Stereochemical Correlations between (2__R__,4′R,8′R)‐α‐Tocopherol, (25__S__,26)‐Dihydroxycholecalciferol, (–)‐(1__S__,5__R__)‐Frontalin and (–)‐(R)‐Linalol

The optically active C~5~‐ and C~4~‐building units 1 and 2 with their hydroxy group at a asymmetric C‐atom were transformed to (–)‐(1__S__,5__R__)‐Frontalin (7) and (–)‐(3__R__)‐Linalol (8) respectively; 1 and 2 had been used earlier in the preparation of the chroman part of (2__R__,4′R,8′R)‐α‐Tocopherol (6a, vitamin E), and for introduction of the side chain in (25__S__,26)‐Dihydroxycholecalciferol ((25__S__)‐4), a natural metabolite of Vitamin D~3~. The stereochemical correlations resulting from these converions fit into a coherent picture with those correlations already known from literature and they confirm our earlier stereochemical assignments. A stereochemical assignment concerning the C(25)‐epimers of 25,26‐Dihydroxycholecalciferol that was in contrast to our findings and that initiated the conversion of 1 and 2 to 7 resp. 8 for additional stereochemical correlations has been corrected in the meantime by the authors [26].