Enantiocontrolled total syntheses of (-)-physovenine and (-)-physostigmine
摘要:
Enantiocontrolled total syntheses of the Calabar bean alkaloid (-)-physovenine (1) and (-)-physostigmine (2) have been achieved in a concise manner starting from the optically active tricyclic enone 3 employing a Fischer indolization reaction under nonacidic conditions as the key step.
7,7-Dimethyl-6,8-dioxabicyclo[3.3.0]oct-3-en-2-one as a synthetic equivalent of ketodicyclopentadiene: a new route to (−)-physostigmine, (−)-physovenine, and (−)-aphanorphine
摘要:
A new diastercocontrolled route to three alkaloids having a quaternary benzylic stereogenic center, (-)-physostigmine, (-)-physovenine, and (-)-aphanorphine, has been developed using enantiopure 7,7-dimethyl-6,8-dioxabicyclo[3.3.0]oct-3-en-2-one as a synthetic equivalent of chiral cyclopentadienone. (C) 2001 Elsevier Science Ltd. All rights reserved.