72690-79-0Relevant articles and documents
SYNTHESIS OF (-)-2S,3S,11S,12R-2,3,11,12-TETRAPHENYLCROWN-6
Dietl, Ferdinand,Haunschild, Jutta,Merz, Andreas
, p. 1193 - 1198 (2007/10/02)
The synthesis of (-) 2S,3S,11S,12R-2,3,11,12-tetraphenyl-crown-6 from (-)-1S,2S-hydrobenzoin and meso-hydrobenzoin is described.Chemical shifts and vicinal coupling constants of the benzylic protons in the 2S,3S and 11S,12R substructures in the free ligands and in complexes with KSCN and 1-phenylethylammonium bromides and a brief discussion of the related conformational changes are also presented.A detailed procedure for the resolution of racemic hydrobenzoin is given.
Enantioselective Reductions of Aromatic Ketones with Ammonia-Borane Complexes of Chiral Tetraphenyl-18-crown-6 Derivatives
Allwood, Billy L.,Shahriari-Zavareh, Hooshang,Stoddart, J. Fraser,Williams, David J.
, p. 1461 - 1464 (2007/10/02)
Enantioselective reductions of prochiral aromatic ketones with adducts formed between ammonia-borane and (2R,3R,11R,12R)- and (2S,3S,11S,12S)-tetraphenyl-1,4,7,10,13,16-hexaoxacyclo-octadecane, (RRRR)-(3) and (SSSS)-(3), have afforded the corresponding (S) and (R) aromatic secondary alcohols with enantiomeric excesses of 20-67percent.