Synthesis of (RSn)4X6 Adamantanes (X = O, S, Se) in Liquid Ammonia and in the Two-Phase System Liquid Ammonia/THF

The reactions of trisSnBr3 (1) [tris = (Me3Si)3C] and nBuSnCl3 with Na2X (X = O, S, Se) yield the heterocyclic adamantanes 2-6. The reaction of 1 with Na2O is carried out in liquid ammonia under normal pressure at -78 °C to give (trisSn)4O6 (2). However, the reaction of 1 with Na2S and Na2Se under pressure at room temperature results in the formation of (trisSn)4S6 (3) and (trisSn)4Se6 (4). nBuSnCl3 reacts with Na2S and Na2Se in liquid ammonia at -33 °C under normal pressure to give (nBuSn)4S6 (5) and (nBuSn)4Se6 (6), respectively.