D,L-Camphor, sulfonation

Calcium carbonate as support for palladium catalyst, 46, 90 Calcium hydride, 46, 58 D,L-Camphor, sulfonation to d,l-10-camphorsulfonic acid, 46,12 10-Camphorchlorosulfoxide, 46, 56 d,l-10-Camphorsulfonic acid, 46,12 conversion to acid chloride, 45,14 10-Camphorsulfonyl chloride, 45, 56 d,l-10-Camphorsulfonyl chloride,... 

Calcium carbonate as support for palladium catalyst, 46, 90 Calcium hydride, 46, 68 D,L-Camphor, sulfonation to d,l-10-camphorsulfonic acid, 46,12... 

Figure 2. Inter-relationships between viscosity of polyaniline doped with d,l camphor sulfonic acid in solutions of cholorform and m-cresol of increasing m-cresol content and electronic spectra, conductivity, dielectric constant and x-ray diffraction spectra of free-standing films (cast from the 3.0 wt.% solutions of the composition indicated). Viscosity studies and spun films for Vis/UV studies employed 0.33 wt.% solutlons,24 25.

Sulfinic esters, aromatic, by oxidation of disulfides in alcohols, 46, 64 Sulfonation ot d,l camphor to d,l-10-camphorsulfomc acid, 45,12 Sulfoxides, table of examples of preparation from sulfides with sodium metapenodate, 46,79 Sulfur dioxide, reaction with styrene phosphorus pentachlonde to give styrylphosphomc diclilonde, 46,... 

The Pfeiffer Effect (1) is defined as the change in optical rotation of an optically active system (usually a solution of one enantiomer of an optically active compound, called the "environment substance", dissolved in an optically inactive solvent) upon the addition of a racemic mixture of a dissymmetric, optically labile coordination compound. Much work has been done on this Effect (2 - 8) and several mechanisms have been proposed to explain it, which are described in a review by Schipper (2). It is of interest to note that the Effect can occur with racemic mixtures of certain optically labile complex cations (e.g., D.L-[Zn(o-phen)3]2+) whether the environment substance is anionic (d- -bromo-camphor- -sulfonate), neutral (levo-nicotine), or cationic (d-cinchoninium), The most frequently used solvent for the Pfeiffer Effect is water (10), although the Effect is known to occur in other solvents as well (l.it.6). 

Perhaps Wemer s tour de force in the area of polynuclear cobalt(III) complexes was his successful resolution of the hexoP ion (VIII). He prepared this ion and its ethylenediamine analog by heating a basic solution of m-diaquotetramminecobalt(III) sulfate and deduced its structure by observing that the acid cleavage gave back the cis-diaquo complex and cobaltous ion (37). He later resolved the ion into its optical antipodes with d-camphor sulfonic acid and d-bromocamphor sulfonic acid and obtained the D- and l- forms as the bromides (35). His successful resolution... 

Since Werner s pioneering work on optical activity in complex inorganic compounds there have been many important developments in the field. One of the more interesting of these is known as the Pfeiffer effect which is a change in the optical rotation of a solution of an optically active substance e,g, ammonium d-a-bromo-camphor-T-sulfonate) upon the addition of solutions of racemic mixtures of certain coordination compounds (e,g, D,L-[Zn o-phen)z](NOz)2, where o-phen = ortho-phenan-throline). Not all combinations of complexes, optically active environments and solvents show the effect, however, and this work attempts to apply optical rotatory dispersion techniques to the problem, as well as to determine whether solvents other than water may be used without quenching the effect. Further, the question of whether systems containing metal ions, ligands, and optically active environments other than those already used will show the effect has been studied also,... 

Mobile phase MeOH water glacial acetic acid 60 40 0.2 containing 5 mM D, L-10-sodium camphor sulfonate, adjusted to pH 6.0 (RI detection) or MeOH water 60 40 containing 10 mM phosphate buffer and 5 mM sodium pentanesulfonate, pH 6 (UV detection) Flowrate 1... 

In 1931, Pfeiffer and Quehl observed that the optical rotation of a solution of an optically active compound (e.g., ammonium ti-a-bromo-camphor-TT-sulfonate, hereinafter called an environment compound) changes significantly upon the addition of solutions of racemic mixtures of certain coordination compounds (e.g., D,L-[Ni(o-phen)3]Cl2). Brasted and his students, and Dwyer and his co-workers have studied this effect in some detail with particular reference to the source and nature of the effect. Kirschner and his co-workers have also studied the effect and have found considerable evidence in support of the mechanism for this effect described by Dwyer and his co-workers. Kirschner and Magnell" have developed quantitative expressions for the rotation change due to the Pfeiffer effect, and have defined a positive Pfeiffer rotation as an enhancement of optical... 

Gotti et al. [42] reported an analytical study of penicillamine in pharmaceuticals by capillary zone electrophoresis. Dispersions of the drug (0.4 mg/mL for the determination of (/q-penicillaminc in water containing 0.03% of the internal standard, S -met hy I - r-cystei ne, were injected at 5 kPa for 10 seconds into the capillary (48.5 cm x 50 pm i.d., 40 cm to detector). Electrophoresis was carried out at 15 °C and 30 kV, with a pH 2.5 buffer of 50 mM potassium phosphate and detection at 200 rnn. Calibration graphs were linear for 0.2-0.6 pg/mL (detection limit = 90 pM). For a more sensitive determination of penicillamine, or for the separation of its enantiomers, a derivative was prepared. Solutions (0.5 mL, final concentration 20 pg/mL) in 10 mM phosphate buffer (pH 8) were mixed with 1 mL of methanolic 0.015% 1,1 -[ethylidenebis-(sulfonyl)]bis-benzene and, after 2 min, with 0.5 mL of pH 2.5 phosphate buffer. An internal standard (0.03% tryptophan, 0.15 mL) was added and aliquots were injected. With the same pH 2.5 buffer and detection at 220 nm, calibration graphs were linear for 9.3-37.2 pg/mL, with a detection limit of 2.5 pM. For the determination of small amounts of (L)-penicillamine impurity, the final analyte concentration was 75 pg/mL, the pH 2.5 buffer contained 5 mM beta-cyclodextrin and 30 mM (+)-camphor-10-sulfonic acid, with a voltage of 20 kV, and detection at 220 nm. Calibration graphs were linear for 0.5-2% of the toxic (L)-enantiomer, with a detection limit of 0.3%. 

However, most asymmetric 1,3-dipolar cycloaddition reactions of nitrile oxides with alkenes are carried out without Lewis acids as catalysts using either chiral alkenes or chiral auxiliary compounds (with achiral alkenes). Diverse chiral alkenes are in use, such as camphor-derived chiral N-acryloylhydrazide (195), C2-symmetric l,3-diacryloyl-2,2-dimethyl-4,5-diphenylimidazolidine, chiral 3-acryloyl-2,2-dimethyl-4-phenyloxazolidine (196, 197), sugar-based ethenyl ethers (198), acrylic esters (199, 200), C-bonded vinyl-substituted sugar (201), chirally modified vinylboronic ester derived from D-( + )-mannitol (202), (l/ )-menthyl vinyl ether (203), chiral derivatives of vinylacetic acid (204), ( )-l-ethoxy-3-fluoroalkyl-3-hydroxy-4-(4-methylphenylsulfinyl)but-1 -enes (205), enantiopure Y-oxygenated-a,P-unsaturated phenyl sulfones (206), chiral (a-oxyallyl)silanes (207), and (S )-but-3-ene-1,2-diol derivatives (208). As a chiral auxiliary, diisopropyl (i ,i )-tartrate (209, 210) has been very popular. 

Derivatization of chiral arylalkylamines and NMR measurement of the diastereomeric ratios can be conveniently performed using d-camphor-10-sulfonic acid, having the (l/ ,4/ ) configuration49. 

The authors reported the chiral separation of proline and thereonine amino acid up to 20 and 6g, respectively, in a single run. Micropreparative resolution of lecucine was presented. The resolution was discussed with respect to the degree of sorbent saturation with copper(II), elution rate, eluent concentration, temperature, and column loading condition [16]. Weinstein [74] reported the micropreparative separation of alkylated amino acids on a Chiral ProCu column. In another article, a preparative chiral resolution of 3-methylene-7-benzylidene-bicyclo[3.3.1]nonane was achieved on 7.5% silver(I)-d-camphor- 10-sulfonate CSP [75]. Later, Shieh et al. [71] used L-proline-loaded silica gel for the chiral resolution of (ft,5 )-phcnylcthanolaminc as the Schiff base of 2-hydroxy-4-methoxyacetophenone. Gris et al. [76] presented the preparative separations of amino acids on Chirosolve L-proline and Chirosolve L-pipecolic acid CSPs. 

Dimethyl-l-(aryl)pyrimidine-2(l//)-(thio)ones (134a-d) were resolved into enantiomers with D-camphor-10-sulfonic acid and their barriers to racemization determined by polarimetry (80JCS(P1)1599). These barriers deserve comment, since their trend is opposite to what is expected (Scheme 98). 

The simplest method to use is reversible salt formation polarimetric and spectropolari-metric studies of salts of optically inactive polyacids (such as polyacrylic, polyitaconic or poly-p-vinylbenzoic acids) with OA bases (like quinine or nicotine) as well as optically inactive bases (polyvinylpyridines) with OA acids (tartaric, mandelic, t/-camphor-/3-sulfonic or with L-menthylbromoacetate) have been reported by Schulz et al f 176, 177]. They found that the optical activity of the poly-salts affected by the microconfiguration of the polymer chain are quite different from the corresponding salts of OA low-molecular weight compounds the ORD curves of isotactic and atactic poly-2-vinylpyridine salts with D-tar-taric acid were found to be anomalous, with a higher value of rotation for the isotactic polymeric salt but in the case of methacryloylnicotine salts it seems that the observed differences can be explained by the assumption of increased specific rotation of the associated nicotine cations in the polymeric salt [178] and not by a conformational effect. 

---