Chapter 3 – The cyclobutanes

Publisher Summary This chapter provides an explanation of cyclobutane and its derivatives. It summarizes the existing literature on cyclobutanes, its structure, and properties. The chapter also explores how the molecular geometry of over 200 derivatives of cyclobutane and cyclobutene are obtained using X-ray methods. In this context, the chapter specifies how the Cn.m.r. spectra of cyclobutane, seven methylated homologues, and some cyclobutane carboxylates have been measured and the substituent parameters for the methyl groups have been calculated. The synthesis of the cyclobutane ring system is then described, beginning with cycloaddition reactions, moving on to intramolecular cyclisations, ring expansion reactions, and concluding with ring contractions. The chapter then addresses the reactions of cyclobutanes where it describes the solvolyses and rearrangements of cyclobutanes and cyclobutenes, electrocyclic ring opening-ring closing reactions, and miscellaneous reactions of cyclobutanes and cyclobutenes. As part of the reactions of cyclobutanes, the reactions of cyclobutanols, cyclobutanones, and cyclobutenones, reactions of cyclobutenenitriles, and reactions of squaric and semisquaric acids are also described.