Premium
Does a chiral alcohol really racemize when its OH group is protected with Boyer's reaction?
Author(s) -
Fraschetti Caterina,
Speranza Maurizio,
Filippi Antonello
Publication year - 2010
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20710
Subject(s) - chemistry , racemization , moiety , alcohol , protecting group , group (periodic table) , diastereomer , walden inversion , catalysis , stereochemistry , organic chemistry , alkyl
Chiral reactants have been employed for assessing the real stereochemistry of the BiBr 3 ‐catalyzed synthesis of benzylic ethers, a very useful reaction for protecting alcoholic groups. The results of this investigation are in clear contrast with the conclusions of previous studies (Boyer et al., Tetrahedron 2001;57:1917–1921). Indeed, chiral GC‐MS analysis of the ethereal products gives unequivocal evidence of the complete racemization of the benzylic moiety and the complete retention of configuration of the protected alcoholic substrate. Such findings make BiBr 3 a powerful and stereochemically preservative catalyst for benzylation of chiral alcohols, and a potential candidate for orthogonal protecting group strategies applicable to polyhydroxy compounds. Chirality 2010. © 2009 Wiley‐Liss, Inc.