Short stereocontrolled synthesis of trans and cis-tetrahydro-pyrazinoisoquinolinediones
作者:Juan Francisco González、Elena de la Cuesta、Carmen Avendaño
DOI:10.1016/s0040-4039(03)00897-9
日期:2003.6
Addition of aldehyde dimethyl acetals (here acetaldehyde) to unisolated O-trimethylsilyl derivatives of 1-acetyl-3-arylmethylpiperazine-2,5-diones (here 2,5-dimethoxyphenyl), in the presence of TMSOTf as the catalyst, gave nearly quantitatively the corresponding N-methoxyalkyl derivatives which, under acidic treatment, gave in very good yield through a Pictet–Spengler-type reaction involving N-acyliminium
在TMSOTf作为催化剂存在下,将醛二甲基乙缩醛(此处为乙醛)加至1-乙酰基-3-芳基甲基哌嗪-2,5-二酮(此处为2,5-二甲氧基苯基)的未分离的O-三甲基甲硅烷基衍生物中相应的N-甲氧基烷基衍生物,在酸性条件下,通过涉及N-酰基阳离子(6 S *,11a R *)-2-乙酰基-6-烷基-3的Pictet-Spengler型反应,具有很高的收率, 6,11,11a-tetrahydro-2 H -pyrazino [1,2- b]异喹啉-1,4-二酮。11a-立体异构体的差向异构化是通过自由基溴化,自发氢溴酸盐消除和催化氢化来完成的,得到(6 S *,11a S *)异构体。我们提出这些化合物作为四氢异喹啉抗肿瘤抗生素的前体。