Syntheses based on norfluorocurarine. 7. Reduction of norfluorocurarine and fluorocurarine by metallic sodium and sodium borohydride

Reduction of norfluorocurarine by sodium in EtOH formed deoxytetrahydronorfluorocurarine and tetrahydronorfluorocurarine. The latter was identical to the Wieland–Humlich 18-deoxyglycol. Reduction of norfluorocurarine by sodium borohydride in alkaline solution occurred with opening of rings C and E and formation of the new indole base 16-decarbmethoxyepistemmadenine. Reduction of fluorocurarine chloride or iodide by sodium borohydride formed the corresponding de-acetylretuline salts. The structures of the products were established by x-ray crystal structure analyses. Norfluorocurarine and representatives of the α-methylenindolenine series formed indoline derivatives upon reduction in acidic and neutral solutions; indole derivatives, in alkaline solution.