Synthesis 2003(6): 0940-0955
DOI: 10.1055/s-2003-38675
FEATUREARTICLE
© Georg Thieme Verlag Stuttgart ˙ New York

Applications of Size-Selective Macrolactonizations to the Synthesis of Benzolactone-Enamide Core Structures

Andreas F. Petri, Sven M. Kühnert, Frank Scheufler, Martin E. Maier*
Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
Fax: +49(7071)295137; e-Mail: martin.e.maier@uni-tuebingen.de;
Further Information

Publication History

Received 13 February 2003
Publication Date:
16 April 2003 (online)

Abstract

By utilizing Stille cross-coupling reactions four benzoic acid derivatives (18, 32, 46, 66) were prepared that carry a side chain with two secondary hydroxy groups. It could be shown that the hydroxy functions can be distinguished by size-selective macrolactonization reactions. Thus, 12-membered lactones 19 and 33 are favored over their 11-membered lactone counterparts 20 and 34, respectively, albeit with a low (60:40-70:30) ratio. The selectivity is much more pronounced if there is a competition between a 12- and 10-membered lactone. This could be shown with the two lactones 47 and 67. The 12-membered lactones 33, 47, and 67 represent core structures for analogs of the benzolactone enamides. The macrolactonization reactions were performed under Yamaguchi conditions.