The reactions of 1-bromo-, 2-bromo-, 1,3-dibromo-and 1,4-dibromoadamantane with À CH 2 NO 2 anions were studied in DMSO and in liquid ammonia. The photostimulated reaction of 1-haloadamantane (1-AdX, X = Br, I) or 2-AdBr with À CH 2 NO 2 anions gave good yields of the substitution product 1-AdCH 2 NO 2 and 2-AdCH 2 NO 2 , respectively, in the presence of the enolate anions of acetone (entrainment conditions). On the other hand, 1-adamantanol was the main product of the reaction performed in DMSO without irradiation, but not in liquid ammonia. 1,3-Dibromo and 1,4-dibromoadamantane reacted with À CH 2 NO 2 anions under irradiation in the presence of the enolate anions of acetone. The first compound gave the disubstitution product 11, and the second the monobromo-substitution products 15 and 16, together with the disubstitution product 17. Compounds 15 and 16 were shown to be intermediates in the formation of 17.

The reactions of 1-bromo-, 1-iodo-, 2-bromo-, 1,3-dibromo-, and 1,4-dibromoadamantane with Me(3)Sn(-) ions were studied in liquid ammonia. The photostimulated reaction of 1-haloadamantane (1-XAd, X = Br, I) or 2-BrAd with Me(3)Sn(-) ions gave in a few minutes excellent yields of the substitution products. The 1,3-dibromo- and 1,4-dibromoadamantane with Me(3)Sn(-) ions also reacted very fast under irradiation to give the disubstitution product in good yields. In competition experiments, 1-ClAd is 5.3 times more reactive than 5-chloro-2-adamantanone (9) toward Me(3)Sn(-) ions in liquid ammonia. When the nucleophile is the Ph(2)P(-) ion, 1-ClAd reacts 2.4 times faster than 9. This is the first time that no redox catalysis was observed when the bridgehead compound bears a carbonyl group as a pi acceptor. On the other hand, the nucleophile Me(3)Sn(-) ion was ca. >1000 times more reactive than Ph(3)Sn(-) ions toward 1-adamantyl radicals, in contrast to the behavior of aryl radicals, where both nucleophiles have the same reactivity.

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