72690-79-0

Upstream product

• 134-81-6 benzil 
• 98769-47-2 (+/-)-(1,2-diphenyl-1,2-ethanedioxy)-diacetic acid 
• 98769-48-3 meso-(1,2-diphenyl-1,2-ethanedioxy)-diacetic acid 
• 655-48-1 DL-1,2-diphenylethane-1,2-diol 
• 579-43-1 (1S,2R)-1,2-diphenylethane-1,2-diol 
• 80158-28-7 (1R*,2S*)-2,2'-(1,2-Diphenylethandiyldioxy)diethanol 
• 80158-27-6 (+/-)-2,2'-(1,2-diphenyl-1,2-ethanedioxy)-diethanol 
• 119-53-9 2-hydroxy-2-phenylacetophenone 
• 6315-52-2 1,2-bis-tosyloxyethane 
• 4721-02-2 (Z)-stilbenediol 
• 78502-13-3 2,3,11,12-Tetraphenyl-2,3,11,12-didehydro<18>krone-6 

Relevant academic research and scientific papers

SYNTHESIS OF (-)-2S,3S,11S,12R-2,3,11,12-TETRAPHENYLCROWN-6

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

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.

Synthesis and Complex Formation of Phenyl- and (4-Phenylbutyl)-substituted Crown Ethers

A number of phenyl and (4-phenylbutyl) derivates of 18-C-6 and 24-C-8 have been prepared: tetraphenyl-diene-18-crown-6 (TPDE-18-C-6), tetraphenyl-18-crown-6 (TP-18-C-6), tetraphenyldiene-24-crown-8 (TPDE-24-C-8), tetraphenyl-24-crown-8 (TP-24-C-8), and bis(4-phenylbutyl)-18-crown-6 (BPB-18-C-6).The ring formation reactions have been carried out by phase-transfer catalysis.All compounds are solids at room temperature except for the liquid BPB-18-C-6 wich represents a mixture of isomers.The syn- and anti-isomers of TP-18-C-6 and TP-24-C-8 have been isolated and identified by x-ray diffraction.The complex formation constants, determined by d. c. polarography in methanol/benzene (80:20 v/v), depend not only on the ring size but also on the number and kind of substituents as well as their steric arrangement.The derivatives of 18-C-6 form the most stable complexes with K+, Sr2+, Ba2+, and Pb2+.The derivatives of 24-C-8 prefer K+, Rb+, and Ba2+.

Synthesis and Ligand Properties of the 2,3,11,12-Tetraphenylcrown-6 Diastereomers

The synthesis and the assignment of the complete set of diastereomers 2a-e of 2,3,11,12-tetraphenylcrown-6 are described.The trans-anti-trans isomer 2d is identified by chiral interaction of optically active 1-phenylethylammonium hydrobromides with the racemic crown ether shown by NMR spectroscopy.Complex association constants of the new crown ethers with sodium, potassium, and ammonium picrates are discussed in terms of the geometry of the diastereomers.