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Synthesis of Thienodolin
Author(s) -
Engqvist Robert,
Javaid Atif,
Bergman Jan
Publication year - 2004
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200400073
Subject(s) - chemistry , formylation , nucleophilic substitution , thiophene , intramolecular force , total synthesis , ring (chemistry) , indole test , electrophilic substitution , stereochemistry , medicinal chemistry , organic chemistry , catalysis
We report a total synthesis of the alkaloid thienodolin ( 1a ), as well as its 5‐chloro isomer 1b and its unsubstituted analogue 1c , in three steps from the corresponding oxindoles 8a − c . The preparation was achieved through an initial Vilsmeier−Haack−Arnold reaction (chloro‐formylation) followed by protection at the indole nitrogen, creation of the fused thiophene ring by nucleophilic substitution at the 2‐position and an intramolecular cyclization using mercaptoacetamide. This gave 1a , 1b and 1c in total yields of 42%, 35% and 37%, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)