D-Camphorsulphonic acid

When heated with acids or alkalis, hyoscyamine undergoes hydrolysis into tropine and dZ-tropic acid probably via conversion into atropine, and it is this alkaloid which is hydrolysed. According to Gadamer, when hyoscyamine is hydrolysed with cold water the products are inactive tropine and Z-tropie acid. Amenomiya has shown that Ladenburg and Hundt s partially synthetic d- and Z-atropines were probably mixtures of atropine with d- and Z-hyoscyamines. He resolved dZ-tropic acid into the d- and Z- forms, esterified these with tropine in 5 per cent, hydrochloric acid, and so obtained d- and Z-hyoscyamines, the latter identical with the natural alkaloid, d- and Z-Hyoscyamines have also been obtained by Barroweliff and Tutin by the resolution of atropine by means of d-camphorsulphonic acid. 

By combining a-aminophenylacetic acid with d-camphorsulphonic acid Betti and Mayer in 1908 separated it into its isomers. This seems to be the first case in which the basic function of an amino acid has been requisitioned for purposes of separation in all the above cases, the acidic function, by combination with optically active bases, has been made use of... 

D-Camphorsulphonic acid 23 has been used to separate the 24 -d form from the d,l-oc-aminophenylacetic acids-l-14C mixture. The former was used in a four-step synthesis27 of one of the most useful semisynthetic antibiotics, ampicillin (25). 

Resolution of two heterocyclic compounds is reported. Partial resolution of the phosphonium salt (151) was achieved using silver d(—)- and l(+)-dibenzoyltartrates, and the phosphine oxide (152) was resolved using (+ )-9-camphorsulphonic acid. ... 

The application of circular dichroism, optical rotatory dispersion, and polarimetry in organic stereochemistry has been reviewed by Snatzke. The easily prepared, non-deliquescent n-propyl- and n-butyl-ammonium salts of d-lO-camphorsulphonic acid have been used to improve the precision of the calibration of circular dichro-meters." ... 

X-Lupanine. After separation of d-lupanine from df-lupanine (see above), the bases are recovered from the mother liquors as lupanine hydriodide, from which clean base is regenerated. This, on combination with U camphorsulphonic acid in acetone, yields 1-lupanine I-camphorsulphonate. 

Dehydrocorydaline contains four methoxyl groups. On reduction it furnishes two stereoisomerides of corydaline, m.p. 135°, and m.p. 158-9° (163-4° vac.), Spath) the latter (wcsocorydaline) by crj stallisation of the d-camphorsulphonate can be partially separated into d- and 1-forms, the d-form of which is not identical with natmal corydaline. The second isomeridc, m.p. 135°, has not been resolved into optically active components, but from the sulphonic acid the Z-compoiicnt has been isolated by crystallisation of the brucine salt, and this is taken to indicate that the inactive corydaline, m.p. 135°, is dZ-corydaline. °... 

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