Cryptopine constitution

The reverse change, viz., the conversion of berberine derivatives by iV-methylation into substances constituted similarly to corresponding derivatives of cryptopine, was achieved by the methylation of dihydroanhydroberberine, to the methochloride, which corresponds to tsocrypto-pine chloride and resembles it closely in character and reactions,... 

Brown and Dyke (93, 93a) (Scheme 9) have elucidated the structure of anhydrocryptopine (IV), epicryptopirubine (V), epicryptopine A (VI), epicryptopine B and C (VII), and -cryptopine (VIII) i.e., the degradation products of cryptopine which were found by Perkin (376) during his classical studies of the constitution of cryptopine. This problem was also studied by Onda et al. (363b, 363c) who obtained dihydrosanguinarine by photocyclization of anhydrocryptopine. 

Gadamer and KoUmar (167) were the first who studied the oxidation of protopine, cryptopine, and allocryptopine by using mercury(II) acetate the final constitution of... 

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