Kinetic monoalkylation of 3,6-dimethoxy-l,4-dimethyl-2,5-piperazinedione 2a via its anion gave a single stereoisomer (3) in which two methoxy groups are in the same side. Acid catalyzed equilibrium of 3 gave a mixture of 3 and its stereoisomer 4 in about 1:1 ratio. Acylation also gave a monoacylated product.
3,6-二甲氧基-1,
4-二甲基-2,5-
哌嗪二酮2a通过其阴离子的动力学单烷基化得到单一立体异构体(3),其中两个甲氧基在同一侧。3 的酸催化平衡得到约 1:1 比例的 3 及其立体异构体 4 的混合物。酰化也得到单酰化产物。