Racemic alpha-epimerizable and unfunctionalized aldehydes have been converted into enantiomerically enriched mixtures through a sequence of (i) a conversion into the diastereoisomeric 3-substituted 1-phenyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazines by reaction with the (R)- or (S)-1-(alpha-aminobenzyl)-2-naphthol (Betti's base), (ii) an acid promoted crystallization-induced diastereoisomer transformation (CIDT), and (iii) a clean cleavage of the dihydro-1,3-naphthoxazinic ring of the enriched diastereoisomer, easily collected by filtration, allowing the recovery of the enantiomerically enriched aldehydes and the chiral auxiliary.
G. Rosini, C. Paolucci, F. Boschi, E. Marotta, P. Righi, F. Tozzi (2010). Acid promoted CIDT for the deracemization of dihydrocinnamic aldehydes with Betti's base. GREEN CHEMISTRY, 12(10), 1747-1757 [10.1039/c0gc00013b].
Acid promoted CIDT for the deracemization of dihydrocinnamic aldehydes with Betti's base
ROSINI, GOFFREDO;PAOLUCCI, CLAUDIO;BOSCHI, FRANCESCA;MAROTTA, EMANUELA;RIGHI, PAOLO;
2010
Abstract
Racemic alpha-epimerizable and unfunctionalized aldehydes have been converted into enantiomerically enriched mixtures through a sequence of (i) a conversion into the diastereoisomeric 3-substituted 1-phenyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazines by reaction with the (R)- or (S)-1-(alpha-aminobenzyl)-2-naphthol (Betti's base), (ii) an acid promoted crystallization-induced diastereoisomer transformation (CIDT), and (iii) a clean cleavage of the dihydro-1,3-naphthoxazinic ring of the enriched diastereoisomer, easily collected by filtration, allowing the recovery of the enantiomerically enriched aldehydes and the chiral auxiliary.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
