This book, which is the first of a series devoted to the chemistry of pyrrole and its derivatives, presents the basic structural, physical and chemical properties of 1H-pyrrole and of the less prevalent 2H-and 3H-isomers, together with the synthesis of the three systems. Since its inital detection in coal, tar and bone oil by Runge in 1834, pyrrole has been an intriguing compound; one which, although being highly susceptible to oxidation and polymerization, occupies a key role in life. Such was its importance as the basic nitrogen heterocycle in porphins and chlorins that much of our early knowledge of the simple ring system revolved around the biologically more important derivatives.