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(equation presented) A unique calix[4]arene lower-rim intramolecular rearrangement, resulting in molecular asymmetry arising from the upper- and lower-rim substitution pattern, produces a new class of inherently chiral calix[4]arenes in a partial cone conformation. This was aided by molecular rigidification arising from π-π and C-H⋯π interactions between bulky lower-rim substituents, with the corresponding circular dichroism spectra exhibiting the most intense bisignate Cotton effects yet observed for calix[4]arenes not bearing a chiral center.

Excellent direct separation of various carboxylic acid and amine enentiomers was accomplished by HPLC on reversed-phase silica gels coated with copper(II) complexes of N,S-dioctyl- d -penicillamine and ( R , R )-tartaric acid mono-( R )-1-( α -naphthyl)ethylamide. The chiral recognition mechanism is discussed. These copper(II) complexes are promising as chiral stationary phases for the separation of a variety of racemic carboxylic acids and amines in which copper(II) complex formation can be assumed.

The chromatographic properties of urea derivatives derived from ( S )- and ( R )-1-( α -naphthyl)ethylamine with ( S )-valine, ( S )- tert .-leucine, ( S )-proline and ( S )-indoline-2-carboxylic acid bonded to 3-aminopropylsilica gel as chiral stationary phases were examined by HPLC to investigate the effect of the structure of the amino acid moiety. The specific enantiomer separation of various racemic compounds including alcohols, esters, amines, amino alcohols, carboxylic acids and amino acids was accomplished on these phases using normal mobile phases. The effect of the stereochemical structure in these urea derivatives on chiral recognition is discussed.

For the separation of carboxylic acid enantiomers by HPLC, the chromatographic properties of four chiral amide and urea derivatives [ N -3,5- dinitrobenzoyl - d -1-(α- naphthyl)glycine , 3,5- dinitrophenylaminocarbonyl - d - phenylglycine , 3,5- dinitrophenylaminocarbonyl - l - valine and 3,5- dinitrophenylaminocarbonyl - l -tert.- leucine ] covalently bonded to 3-aminopropylsilanized silica gel as chiral stationary phases were examined. Direct separation of various carboxylic acid enantiomers was accomplished with these chiral stationary phases. The influence of the composition of the mobile phase in these enantiomer separations was shown. Amino acid enantiomers were also well resolved in the form of their derivatives containing a free carboxylic acid group, such as tert.-butoxycarbonyl (t-BOC), benzyloxycarbonyl (Z), 9-fluorenylmethoxycarbonyl (FMOC) and 5-dimethylamino-1-naphthalenesulfonyl (dansyl) derivatives.

Three mono-amide derivatives of (R,R)-tartaric acid derived from (R)-1 -(α-naphthyl)ethylamine (I), (S)-valine-(S)-1-(α-naphthyl)ethylamide (II) and (R)-valine--(R)-1-(α-naphthyl)ethylamide (III) were prepared and their chromatographic properties as chiral selectors were examined by HPLC. The enantiomeric separation of derivatives of racemic amino acids, amines, carboxylic acids and alcohols was achieved with these chiral selectors ionically bonded to 3-aminopropyl silica gel using organic mobile phases. In this separation the chiral amine or amino acid amide moiety may play an important role in chiral recognition. On the other hand, the direct separation of racemic amino acids and hydroxy acids was accomplished with these chiral selectors in the form of copper(II) complexes coated on the reversed-phase materials using aqueous mobile phases containing copper(II) ions. In this separation the (R,R)-tartaric acid moiety may contribute to the chiral recognition. These results clearly show that these (R,R)-tartaric acid mono-amide derivatives can act as bifunctional chiral selectors, and they are promising for the enantiomeric separation of a wide range of racemic compounds by HPLC.

A new cellulose derivative, sodium deoxycellulosesulfonate was prepared by a nucleophilic substitution of cellulose p-toluenesulfonate (cellulose tosylate) with sodium hydrogensulfite under refluxing in water. Degree of substitution of water-insoluble fraction of the sulfonate increased with reaction time and it was about 0.10 for cellulose tosylate with DS of 0.92 and 0.065 for that with DS of 0.79 at 24h, respectively. Yield of the insoluble sulfonates decreased with reaction time and showed a value as low as 48mol% for cellulose tosylate with DS of 0.92 at 48h. Conversions of the p-toluenesulfonate group to the sulfonate group were 11 and 8.2mol% for cellulose tosylates with DS of 0.92 and 0.79 at 24h, respectively, and p-toluenesulfonate group still remained even after the reaction of 48h. The sodium deoxycellulosesulfonate was identified by dyeing test with Methylene Blue for acid group, micro combustion test for sulfur, incineration test for sulfonate and sulfate groups, and hydrolysis-in-cineration test for sulfonate group, as well as with IR absorption spectra.

Copper(II) complexes of Schiff bases of chiral amino alcohols were examined as chiral ligand-exchange phases for high-performance liquid chromatography. The direct separation of a large number of amino alcohol, amine, amino acid and hydroxy acid enantiomers was accomplished using octadecylsilanized silica coated with the binuclear copper(II) complex of N-salicylidene-( R )-2-amino-1,1-bis(2-butoxy-5- tert. -butylphenyl)-3-phenyl-1-propanol ( 1 ) and water or water—organic eluents containing copper(II) ion as mobile phases. The interaction of various enantiomers with the copper(II) complex 1 for chiral discrimination was discussed.

Ultraviolet absorption (UV) and electronic circular dichroism (ECD) spectra of enantiopure (Z)-8-methoxy-4-cyclooctenone (MCO) were measured in hexane to give a normal single UV absorption band at 298 nm, which is assigned to the carbonyl's pi*

Starting from the corresponding 8-membered cyclic 1,2-diones, spiro-bridged cyclic dimers were prepared in moderate to good yields via barium oxide/hydroxide mediated coupling, followed by in situ methylation with dimethyl sulfate.