5-disubstituted quinuclidines were obtained stereoselectively from 4-bromoacetylpiperidine (7) to give (1a) and (1b) (9:1) or by Dieckmann cyclisation of piperidine (9) to give ketals (13a) and (13b) (9:1). Pyrrolidine triester (14) gave exclusively the -1-azanorbornane ester (15a). Epimerisation of (13a) and (15a) gave (13b) and (15b) respectively as the thermodynamic products.
从4-
溴乙酰基
哌啶(7)立体选择性地获得3,5-二取代的奎尼啶,得到(1a)和(1b)(9:1)或通过
哌啶的Dieckmann环化(9)得到
缩酮(13a)和(13b)( 9:1)。
吡咯烷三酯(14)仅产生-1-氮杂降
冰片烷酯(15a)。(13a)和(15a)的差向异构化分别得到(13b)和(15b)作为热力学产物。