Camphoric anhydride

Camphoric anhydride [595-30-2] M 182.2, transitn temp 135 , m 223.5 . Crystd from EtOH. 

The present method is adapted from that of Loven. The resolution has been carried out with d-a-bromocamphor-TT-sulfonic acid (f-form) 2.3 with /-and d/-malic acids (d- and /-forms) with /-quinic acid and d-tartaric acid (d- and /-forms) and with d- and /-6,6 -dinitrodiphenic acids (d- and /-forms). Methods employing d-benzyimethylacetyl chloride, d-oxymeth-ylenecamphor, /-quinic acid, and d-camphoric anhydride are of theoretical interest only. The d/-amine is not resolved by the active camphor-lo-sulfonic acids or mandelic acids. ... 

Very low asymmetric induction (e.e. 0.3-2.5%) was noted when unsymmetrical sulphides were electrochemically oxidized on an anode modified by treatment with (— )camphoric anhydride or (S)-phenylalanine methyl ester299. Much better results were obtained with the poly(L-valine) coated platinum electrodes300. For example, t-butyl phenyl sulphide was converted to the corresponding sulphoxide with e.e. as high as 93%, when electrode coated with polypyrrole and poly(L-valine) was used. 

Low asymmetric induction (e.e. 0.3-2.5%) was found (56) to occur when unsymmetrical sulfides were electrochemically oxidized on an anode modified by treatment with (->camphoric anhydride or (5)-phenylalanine methyl ester. 

Camphoric anhydride with benzyl chloride gives two isomeric campholides ... 

The complete process was as follows camphoric anhydride from camphoric acid was reduced with sodium amalgam to campliolide, and this combined with potassium cyanide gave homocamphoric nitrile. The nitrile was hydrolysed, and the calcium salt of the resulting homocamphoric acid, on heating, gave camphor ... 

Camphoric Anhydride -> Campholide -> Homo-camphoric- Acid,... 

Camphoric anhydride is prepared by mixing camphoric acid (100 gms.) with acetic anhydride... 

In curve c the water reaction is predominant, as in the hydration of camphoric anhydride at 25° (Wilsdon and Sidgwick, 28). 

The results obtained with camphorquinone in -xylene are of particular interest since this reaction has been investigated 129> under otherwise identical conditions in the presence and absence of oxygen. In carefully degassed -xylene solution at 4358 A the major products were the 1,2-adducts 56 and 57 the quantum yield for disappearance of dione was 0.07. In air-saturated -xylene the quantum yield increased to 0.16, 56 and 57 were not formed, instead the products were camphoric acid (104) and camphoric anhydride (105). No explanation has been offered for the different course of reaction in benzene where cyclic lactones 106 and 107 were obtained 97). Intermediacy of the cyclic diacyl peroxide 108 has been suggested 97h It is tempting to speculate that the diacyl radical 109 may have been trapped by oxygen. 

Camphorquinone CC14> t-buOH, MeOHb) >3000 camphoric anhydride (105) 97)... 

Camphoric anhydride [595-30-2, 76-32-4] M 182.2, transition temp. 135°, m 223.5°. CrystalUse the anhydride from EtOH. If it contains too much of the acid (check the IR), then reflux it in AC2O, concentrate and collect the crystals, wash them with petroleum ether and dry them in vacuo. [Bunton et alJ Chem Soc 2918 1963, NMR Baker Davis Tetrahedron 24 1663 1968, Beilstein 18 H 400,401.]... 

HjjO. Df 1-0998. nil 1-47372 Dist. ethyl ester + camphoric anhydride. 

The potential of a combined NMR/MD/QM approach has been explored by Aliev et al as a universally applicable technique for full structure and dynamics characterizations of cycKc compounds in solutions. Experimental and quantum mechanical-predicted values of Vhh coupUngs, chemical shifts, and interproton distances have been used for comprehensive verifications of structures derived from the MD/QM analysis of three benza-zocinone derivatives with fused five- and eight-membered aliphatic rings, camphoric anhydride and bullvalene. 

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