Indolizidine 209D (2) was synthesized in 11 steps from L-aspartic acid (3) in an overall yield of 16%. 3R-pyrrolylnonanoic acid, prepared from 3, was converted into the α-keto diazomethyl derivative, which on Rh2(OAc)4-catalyzed cyclization and catalytic hydrogenation gave 2. A similar procedure, starting from 3, afforded 3R-pyrrolylhexanoic acid, an intermediate which had previously been converted
                                    从
L-天门冬氨酸(3)以11个步骤合成了Indolizidine 209D(2),总产率为16%。将由3制备的3R-
吡咯基
壬酸转化为α-酮重氮甲基衍
生物,在Rh 2(OAc)4催化下环化和催化加氢得到2。从3开始,类似的方法得到3R-
吡咯基
己酸,该中间体先前已经在3步中转化为
吲哚并立定167B。