Progress in Heterocyclic Chemistry Volume 5 deals critically with original material selected essentially from the 1992 heterocyclic literature. Chapters 1 and 2 are given over to reviews: in the first, SO2 extrusion from five-membered rings is discussed by R.A. Aitken and colleagues, which completes last year''s review on this topic. The second review presents a review of 2-acylamino-3-dimethylaminopropenoates in heterocyclic synthesis. The chapters are arranged according to ring sizes as in the previous volumes and are supported by references, numerous diagrams and a subject index.