Chapter 11 - Polycarbocyclic Bridged Ring Compounds

Abstract

Publisher Summary The rigid nature of the polycarbocyclic bridged systems makes them attractive building blocks for stereoselective syntheses. These systems are widely used in the synthesis of prostaglandins, juvabione, and of one of the key degradation products in the determination of the structure of diterpenoid resin acids. This chapter discusses the preparation and general properties of polycyclic bridged ring compounds. Several methods employed for the synthesis of polycyclic bridged ring compounds are—(1) by the Diels–Alder reaction, (2) from salts of cyclic di-β-ketoesters, and (3) by solvolytic methods. The rigid nature of bridged polycyclic compounds allows very precise correlations to be made of spin–spin coupling data and substituent shift effects. For this reason nuclear magnetic resonance offers a much more powerful aid to the solution of structural problems than it does in applications related to more flexible molecules. Several polycyclic bridged ring compounds discussed in the chapter are the bicyclo [1.1.1] pentane group, the bicycle [2.1.1] hexane group, the bicycloheptane group, the bi- and tricyclooctane group, and the polycyclo [3.3.1] nonane group.