Synthesis 2008(14): 2177-2182  
DOI: 10.1055/s-2008-1067143
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Cyclobutane Ring Opening Reactions of 1,2,2a,8b-Tetrahydrocyclobuta[c]-quinolin-3(4H)-ones

Philipp Selig, Thorsten Bach*
Lehrstuhl für Organische Chemie I, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
Fax: +49(89)28913315; e-Mail: thorsten.bach@ch.tum.de;
Further Information

Publication History

Received 15 April 2008
Publication Date:
18 June 2008 (online)

Abstract

Two pathways are presented, which allow for the selective cleavage of the C1/C8b bond in the title compounds. The first reaction was found by serendipity when reductive debenzylation was attempted on a heteroanellated azabicyclo[4.2.0]octane. It yielded an eight-membered lactam ring (azocane). The second transformation relies on a rationally designed 1,2-rearrangement reaction, which was introduced because attempts to induce classical Wagner-Meerwein-type 1,2-shifts did not meet with success. The reaction, a retro-benzilic acid rearrangement, allowed for the conversion of a heteroanellated hydroxycyclobutanecarboxylate into the respective cyclopentadione (76% yield).

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Preliminary communication: Selig, P.; Bach, T. Angew. Chem. Int. Ed. 2008, 47, in press.