Premium
Über die Chemie des Vitamins E. 3. Mitteilung. Die Totalsynthese von (2 R , 4′ R , 8′ R )‐ und (2 S , 4′ R , 8′ R )‐α‐Tocopherol
Author(s) -
Mayer H.,
Schudel P.,
Rüegg R.,
Isler O.
Publication year - 1963
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19630460225
Subject(s) - chemistry , diastereomer , enantiomer , tocopherol , hydrolysis , stereochemistry , bromide , vitamin e , antioxidant , organic chemistry
(2 R , 4′ R , 8′ R )‐ and (2 S , 4′ R , 8′ R )‐α‐tocopherol have been synthesized by W ITTIG reaction of the two enantiomeric S‐(+)‐ and R‐(−)‐6‐acetoxy‐Z‐formyl‐2,5,7, 8‐tetramethyl‐chromans (I) with (3 R , 7 R )‐hexahydrofarnesyl‐triphenylphosphonium bromide (II), followed by hydrogenation and hydrolysis. (2 R , 4′ R , 8′ R )‐α‐tocopherol proved to be identical in every respect with natural so called d‐α‐tocopherol. Resolution of the chroman component was achieved via the diastereomeric quinine salts of 2‐carboxyethynyl‐6‐hydroxy‐2,5,7,8‐ tetramethyl‐chroman (XVIII). followed by transformation of the enantiomers into S‐(+)‐ and R‐(−)‐I, respectively.