Book excerpt: Selectivity is an increasingly important part of organic synthesis. The whole basis of organic chemistry, and especially organic synthesis, depends upon the selectivity which can be achieved in organic reactions. This concise textbook describes the strategies which can be adopted to improve selectivity, and the reactions which have been specially designed to afford high selectivity. The aim is to illustrate the range of processes to which these principles can be applied and the high degree of selectivity which can be achieved. Selectivity in Organic Synthesis aims to provide a solid introduction to this subject, focusing on the key areas and applications.