Dedicated in memory of Prof. Gilbert Stork
Abstract
This Short Review highlights various synthetic approaches to bridged azabicyclic ring systems containing seven-membered carbocyclic rings. Such ring systems are common to a number of biologically active natural products. The seven-membered ring in such systems is generally formed in one of four ways: 1) cyclization of an acyclic precursor; 2) ring expansion or rearrangement of a different ring size; 3) cycloaddition; and 4) use of a synthetic building block with the seven-membered ring already present. Representative examples of each approach from both total synthesis and methodological studies are discussed, with an emphasis on work published
in the last twenty years.
1 Introduction
2 Cyclization Reactions
3 Ring Expansions and Rearrangements
4 Cycloadditions
5 Strategies Involving Seven-Membered Ring Building Blocks
6 Conclusion
Key words
alkaloids - heterocycles - rearrangements - natural products - cycloheptane - bridged bicyclic
