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Synthesis and stereochemical characterization of optically active 1,2‐diarylethane‐1,2‐diols: Useful chiral controllers in the ti‐mediated enantioselective sulfoxidation
Author(s) -
Donnoli Maria Irene,
Scafato Patrizia,
Superchi Stefano,
Rosini Carlo
Publication year - 2001
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.1028
Subject(s) - chemistry , stereocenter , absolute configuration , chirality (physics) , enantioselective synthesis , enantiomer , stereochemistry , dihydroxylation , chiral column chromatography , sharpless asymmetric dihydroxylation , catalysis , organic chemistry , nambu–jona lasinio model , chiral symmetry breaking , physics , quantum mechanics , quark
The series of phenylsubstituted 1,2‐diphenylethane‐1,2‐diols 2a–h was prepared in high chemical (70–80%) and optical yields (∼90%) by Sharpless syn ‐dihydroxylation of the corresponding (E)‐1,2‐diarylethenes, in turn obtained by McMurry or Wittig reactions. The enantiomeric excesses of the samples were determined by HPLC analysis using Chiralcel OD chiral stationary phase (CSP). This CSP was able to resolve all the diols, except for 2g , with α values ranging between 1.10–1.64. In all cases the (R,R) antipode was eluted first. (R,R) absolute configuration was assigned to the dextrorotatory (CHCl 3 ) diols 2a–h by analyzing the CD spectra of their 2,2‐dimethyl‐1,3‐dioxolanes 3a–h . In fact, the CD spectra of all these dioxolanes present a positive couplet (210–180 nm range) which can be nonempirically related to an (R,R) absolute configuration of the two stereocenters. Chirality 13:258–265, 2001. © 2001 Wiley‐Liss, Inc.