Premium
Asymmetric biomimetic oxidations of phenols using oxazolidines as chiral auxiliaries: the enantioselective synthesis of (+)‐ and (−)‐dehydrodiconiferyl alcohol
Author(s) -
Bruschi Maurizio,
Orlandi Marco,
Rindone Bruno,
Rummakko Petteri,
Zoia Luca
Publication year - 2006
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1089
Subject(s) - chemistry , enantioselective synthesis , phenols , enantiomer , stereoselectivity , benzofuran , alcohol , hydrogen peroxide , desymmetrization , organic chemistry , chiral auxiliary , ferulic acid , enantiomeric excess , medicinal chemistry , catalysis , food science
Stereoselective bimolecular radical coupling reactions of phenylpropenoid phenols are described. Evans's 2‐oxazolidinone 11a–d derivatives of ferulic acid were prepared and oxidized to give dimeric benzofuran neolignan structures 12–13a–d in 40–50% overall yields. The chiral phenols were dimerized either enzymatically with hydrogen peroxide and horseradish peroxidase (HRP) or with silver oxide. The enantioselectivity after reductive cleavage of the chiral auxiliaries to give dehydrodiconiferyl alcohol ranged from 18% to 62% enantiomeric excess. The conformational analysis and the activation energy using semiempirical PM3 calculations on the intermediate quinomethides is used to explain the observed stereoselectivity. Copyright © 2006 John Wiley & Sons, Ltd.