A new spiro-formation of oxaeolidine-4,5-dione has been reported by us in the reaction of chrysanthemamide with oxalyl chloride (2).
In the present communication, we wish to describe the results of the similar reactions of adamantane-1-carboxamide (Ia) and -carboxanilide (Ib) with oxalgl chloride, both of which resulted in the rearrangement te spirohomoadamantane oxaaolidine-4,5-dione (Va and b) by the treatment of the primary adducts (IIIa and b) with ethanol. Dropwise addition of excess oxalyl chloride to a stirred, ice-cooled suspension of Ia in methylene chloride caused immediate evolution of hydrogen chloride gas and simultaneous clarification of the reaction mixture. While being stirred for about 2 hr at room temperature (ca 200), the clear solution became turbid and white precipitates, No.78 carbonyls at 1830 and 1760, and a weak band at 1680 (C=N+) cm-l, supporting the structure IIIb rather than IVb. This oil was heated in ethanol and cooling of the mixture afforded colorless Crystals, mp 202-208' (dec.), in 56% yield. Its structure was confirmed as 1-ethoxyhomoadamantane-2-spiro-2 *-N-phenyloxazolidine-4',5'-dione Vb (X=OC,EI5) on the basis of the analytical (Found: C, 70.71; II, 6.91; N, 4.13. Calcd for C21H2504N: C, 70.96; H, 7.09; N, 3.94.) and spectral data; the infrared absorption bands at 1815 and 1740 cm-1 indicate the presence of an oxazolidine-4,5-dione ring and phenyl absorption bands at 1600, 740, and 690 cm -1 with no NH bands support Vb structure, while methyl N-chloroacetyloxanilate is shown to have three carbonyl bands at such lower frequencies a6 1768, 1748 and 1720 cm -l(3).