Methods for the formation of substituted bicyclo[3.2.0]heptan-2-ones and bicyclo[3.2.0]heptan-6-ones which are applicable to the large scale production of these compounds as starting materials in synthetic processes are summarised. The means of elaboration of these bicyclo[3.2.0]heptanones and the controlling factors are discussed. Examples of the wide variety of alicyclic molecules available from these bicyclic systems are also described. 1. Introduction 2. Synthesis of Bicyclo[3.2.0]heptanones 2.1. Bicyclo[3.2.0]heptan-2-ones 2.2. Bicyclo[3.2.0]heptan-6-ones 3. Reactions of Bicyclo[3.2.0]heptanones 3.1. Formation of Cycloheptane Derivatives 3.2. Formation of Cyclopentane Derivatives 3.3. Formation of Cyclobutane Derivatives 3.4. Formation of Other Bicyclic Ring Systems