3,5-Dialkyl indolizidines have been prepared in four linear steps from commercially available starting materials. The sequence involves two direct α-functionalization steps and a subsequent reductive amination and provides diastereoselective access to both C-3 epimers of the 5,9-trans-substituted indolizines. The naturally occurring indolizidines 195B and 223AB have been synthesized using this methodology
3,5-二烷基
吲哚并
吡啶类化合物是由市售起始原料按四个线性步骤制备的。该序列涉及两个直接的α-官能化步骤和随后的还原性胺化,并提供对5,9-反式取代的
吲哚嗪的两个C-3差向异构体的非对映选择性。使用这种方法已经合成了天然存在的
吲哚唑烷195B和223AB。