Wenkert-type enamine

Stork and Guthikonda (15) have shown that the cyclization of iminium ion 46 (produced in situ) gave ( )-B-yohimbine (47) and Wenkert and co-workers (22) have further observed that the acid-catalyzed cyclization of enamines of type 48 yielded exclusively product 50 via the cyclization of iminium ion 49. In the last two examples, formation of the C —C bond is the result of a trans-addition on the iminium double-bond in agreement with the principle of stereoelectronic control. 

---

See also in sourсe #XX -- [ , , ]

See also in sourсe #XX -- [ , , ]

---