Camphor, specific rotation

The esierUial oil detived from ihc hoa-rds is filled with crystaJa which have heeo ideotificd as c dtir camphor after purification they melt at 6G to 67 C., and have a specific rotation of + 10T2 ... 

It has the extraordinarily high specific rotation + 426 5°. Phenyl-ethylidene camphor is a faintly greenish oil of specific gravity 1 025 at... 

Camphor, molecular model of, 129 specific rotation of, 296 Cannizzaro, Stanislao, 724 Cannizzaro reaction. 724 mechanism of, 724 Caprolactam, nylon 6 from, 1213 Capsaicin, structure of. 78 -curbahlehyde, aldehyde name ending, 696... 

The 1-dichloro-d-bromo-camphor sulphonie salts are the least soluble. The colour of these optically active derivatives is the same as that of the racemic salts. 1-Dichloro-diethylenediamino-chromie d-a-bromo-camphor sulphonate, [Cren2Cl2]SO3C10H14OBr, forms small, shining violet crystals, and has specific rotation [molecular rotation of [M]D + 176-9°. Solutions of both isomers are rapidly raeemised. 

In special cases of optically active photochromes the change in molecular form is accompanied by a change in specific rotation. Singh (170) noted that as (l-naphthylamino)camphor (0.726 g. in 100 cc. chloroform) turned from colorless to green with a 6-min. exposure to sunlight, the specific rotation changed from 126° to 186.6°. Reversal of the system required days. 

The specific rotation of camphor as 9% solution in chloroform has been determined by using a Perkin Elmer Polarmatic Model 2l+l MC and found to be ... 

Methyl-3-piperidinothietane 1,1-dioxide has been resolved via its tf-camphor-10-sulfonate salt the enantiomer obtained had a specific rotation of... 

Since before the turn of the century it has been known that the optical activity of some chiral compounds is solvent dependent (1 ). For example, in 1877 Landolt (2) reported that the specific rotations of (+)-camphor, (-)-nicotine, (+)-diethyl tartrate, and (-)-turpentine varied with solvent and concentration. In the last decade there has been renewed interest in this solvent dependence. A number of different types of organic compounds has been investigated and the results have been interpreted in terms of variations in conformer populations that have resulted from either the effect of the dielectric on coulombic interactions between dipolar groups in the molecule (3), or from hydrogen-bond interactions between the solvent and the chiral solute (k). 

The resolution of synthetic di-sparteine was achieved by Leonard and Beyler (278, 279) by means of i- and d-jS-camphorsulfonic acid, and both optically active forms of sparteine were obtained. The free bases were not isolated but each enantiomorph was identified through the formation of two known derivatives. The derivatives used to identify Lsparteine were the d-jS-camphorsulfonate and the dipicrate. The former salt was characterized by melting point, mixed melting point with an authentic sample, and specific rotation. The latter salt was characterized by melting point and mixed melting point with authentic I-sparteine dipicrate. d-Sparteine i- 3-camphorsulfonate had a specific rotation equal and opposite to its enantiomorphic Z-sparteine d-/3-camphorsulfonate. Characterization of d-sparteine was accomplished by conversion of the camphor-sulfonate salt to the dipicrate and monoperchlorate, both of which were... 

PROBLEM 5.14 Camphor is optically active. A camphor sample (1.5 g) dissolved in ethanol (optically inactive) to a total volume of 50 mL, placed in a 5-cm polarimeter sample tube, gives an observed rotation of -1-0.66° at 20°C (using the sodium D-line). Calculate and express the specific rotation of camphor. 

Using the Aldrich Handbook, report the specific rotations for the enantiomers of camphor. 

Following the same idea, Minoura et al. [36] mention the melt and solution condensation of nylon salts prepared from r/-camphoric or adipic acid with hexamethylenediamine. The specific rotations for the copolyamides increased with increasing c -camphoryl unit content in the copolymers which obey the simple Drude equation the same polyamides have been obtained also by interfacial condensation. The specific rotation of polyhexa-methylene camphoramide increased markedly with increasing intrinsic viscosity over the range of 0.05 - 0.10 g df. ... 

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. 

Bubatance, which, when iroed from adherent oil, was white and crystalline, and possessed the characteristic odour of camphor. It melted at 174 to 176, and had a specific rotation of F 40 66 in JO per cent, alcoholic solution. Iis corubustiou figures agreed with those for... 

In the following specific substitution pattern, the outcome of the reaction depends on the energy of the transition states of the addition, the rotation and the ring closure, as described by Aggarwal. Although explanations for the diastereoselectivity have been given, the enantioselectivity that is induced by the camphor-derived sulphonium group is not yet fully understood ... 

Siamese cardamom oil is distilled from the seeds of Amotmim carda-momvm, which are known on the market as camphor seeds on account of their camphor-like odour. Schimmel obtained 2-4 percent., which was semi-solid at the ordinary temperature, and had an odour of camphor and borneol. In order to liquefy the oil it was necessary to warm it to 42. Its specific gravity at this temperature was 905, and its optical rotation - - 38 4. It required 1 88 per cent, of KOH to saponify the esters present, and contained alcohols equivalent to 22-5 per cent, of borneol. It was soluble in 1-2 volumes of 80 per cent, alcohol. From 800 grms. of the oil 100 erms. of the solid compounds were obtained by centrifugal action. These were examined and found to consist of about equal parts of dextro-borneol and dextro-camphor. 

The oil distilled from the bark of the root, according to Pilgrim, has a specific gravity 0 994 and optical rotation + 50 . It contains pinene, dipentene, phellandrene, cineol, camphor, eugenol, safrol, bomeol, and oaryophyllene. 

The leaves of the Japan camphor tree also yield an essential oil. According to Hooper the yield is about 1 per cent., the oil having a specific gravity about 0 930 and optical rotation -i- 4 32. It contained... 

An oil reported on by Keimazu is described as having a specific gravity 0 9279. and optical rotation + 17, but this appears to have been mixed with camphor oil, so that his researches as to the constituents present must be accepted with reserve. The principal body present in the oil is the alcohol linalol (Keimazu found formaldehyde, d-a-pinene, cineol, dipentene, apopinol (impure linalol ), camphor, eugenol, and safrol). 

Methods involving the optical rotation of camphor are of little value as synthetic camphor, which is practically devoid of rotatory power, is now used and the rotations of solutions of natural camphor differ according to the solvent. In ethanolic solution the highest specific rotatory power is obtained by measurement of a weak solution of camphor in strong ethanol formulae have been derived to calculate the percentage from rotation in given solvents (Partheil and Van Haaren Schoorl ). 

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