Piperidine, one of the simplest heterocyclic systems, is found in nature as part of several alkaloid compounds. Both natural and especially unnatural piperidine derivatives present interesting pharmacological properties. From a structural viewpoint, the conformation of piperidine has been the subject of one of the fiercest controversies in structural organic chemistry in the last few years. As a result of the combined use of several spectroscopic techniques, the conformational behavior of most types of piperidine-related compounds has been clarified. Some piperidine derivatives, namely, N-acylpiperidine, &agr;-cyanopiperidines and piperidones are extremely useful and versatile intermediates in organic synthesis. The present book offers an updated and integrated view of all these topics. The aim of the book is twofold. Firstly, to reveal to the reader the combined use of different spectroscopic data, to facilitate an insight into the structure and conformational properties of any new piperidine derivative. Secondly, to establish a consistent link between conformation and reactivity for a variety of piperidine derivatives. Such a bridge is a key step for stereocontrol when dealing with the application of piperidine derivatives as synthetic intermediates. The book is conceived so that most of the information comes from visual inspection of the very abundant graphic material. An exhaustive subject index of more than 450 entries is also included.