Synthesis of (+)-2R,3R,11R,12R- and (−)-2S,3S,11S,12S-tetraphenyl-18-crown-6
作者:F. Dietl、A. Merz、R. Tomahogh
DOI:10.1016/s0040-4039(00)85812-8
日期:1982.1
The synthesis of the title crown ethers starting from opticallyactive hydrobenzoins is described. R(+)-1,in CDCl3 ,preferentially extracts R(+)-phenylglycine methyl ester hydroperchlorate from an aqueous solution of the racemate with a chiralrecognition factor of 1.5 as shown by nmr measurements.
An efficient procedure for the synthesis and isolation of (+)-(2R,3R,11R,12R)- and (−)-(2S,3S,11S,12S)-tetraphenyl-18-crown-6
作者:John Crosby、Martin E. Fakley、Colin Gemmell、Keith Martin、Andrew Quick、Alexandra M.Z. Slawin、Hooshang Shahriari-Zavareh、J. Fraser Stoddart、David J. Williams
DOI:10.1016/s0040-4039(01)80675-4
日期:1989.1
reactions from the readily-available chiral precursors, (RR)- and (SS)-hydrobenzoins, followed by bulk isolations of the pure 18-crown-6 derivatives via their 1:1 crystalline complexes with potassium nitrate (for the diphenyl derivative) or calcium nitrate (for the tetraphenyl derivative), obtained directly from the worked-up crude reaction mixtures: X-ray crystal structures characterise the uncomplexed