A synthesis of 11-methoxy mitragynine pseudoindoxyl, a new member of the mitragynine class of opioid agonists, from a derivative of the Geissman-Waiss lactone is described. An internal attack of an electron-rich aromatic ring on an electrophilic nitrilium ion and a late-stage construction of the functionalized piperidine ring by the method of reductive cyclization are the pivotal transformations; both ring annulations proceed in a highly diastereoselective fashion. The construction of substituted indoxyl frameworks by the interrupted Ugi method offers an attractive alternative to the strategy of oxidatively rearranging indoles.
|Original language||English (US)|
|Number of pages||4|
|State||Published - Sep 2012|
All Science Journal Classification (ASJC) codes