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Absolute Configuration Determination of Azulenyl Diols Isolated From Asymmetric Pinacol Coupling
Author(s) -
Dragu Eugenia Andreea,
Naubron JeanValere,
Hanganu Anamaria,
Razus Alexandru C.,
Nica Simona
Publication year - 2015
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.22523
Subject(s) - chemistry , pinacol , absolute configuration , enantiomer , chirality (physics) , enantioselective synthesis , butane , diol , coupling (piping) , stereochemistry , organic chemistry , catalysis , chiral symmetry breaking , physics , quantum mechanics , nambu–jona lasinio model , quark , mechanical engineering , engineering
A convenient enantioselective approach for the pinacol coupling of 1‐acetylazulene involving easily accessible (R)‐ or (S)‐BINOLs as chiral additive is reported. This supposes the preformation of the chiral titanium–BINOL complex in 1:2 ratio and subsequent reduction with zinc when, 2,3‐di(azulen‐1‐yl)butane‐2,3‐diol can be isolated in around 60% enantiomeric excess. The absolute configuration of the isolated enantiomers was assigned by comparison of the experimental and Boltzmann‐weighted calculated VCD and ECD spectra and assigned as (+)‐(2S;3S)‐di(azulen‐1‐yl)butane‐2,3‐diol. Chirality 27:826–834, 2015 . © 2015 Wiley Periodicals, Inc.