ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Reaction of trimethyl-hydroquinone with methyl vinyl ketone in acidic methanol gave rac.-2-methoxy-2,5,7,8-tetramethyl-chroman-6-ol (8). This acetal was converted in four steps to rac.-(6-hydroxy-2,5,7,8-tetramethyl-chroman-2-yl)acetic acid (13). Acid 13 was readily resolved with α-methyl-benzylamine to give the (S)-enantiomer 14. Treatment of the unwanted (2 R)-isomer with acid regenerated 13, thus leading to an efficient use of this compound. Employing a side chain derived from phytol, 14 was converted to (2R, 4′R, 8′R)-α-tocopherol (1d, ‘natural’ vitamin E). A reaction sequence from 14 involving two highly stereoselective Claisen rearrangements has provided the first total synthesis of (2R,'E,7′E)-α-tocotrienol (2d).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19760590135
