Description:(from preface)Volume 51 of Advancesconsists of three chapters, V. V. Mezheritskii and V. V. Tkachenko (Rostov-on-Don, U.S.S.R.) review the synthesis of peri-annelated heterocycles, a large and interesting class which has not previously been treated in a systematic fashion. R. M. Acheson (Oxford, U.K.) provides the first detailed survey of l-hydroxypyrroles and their benzo derivatives, compounds which show an interesting and unusual chemistry. Finally, B. A. Trofimov (Irkutsk, U.S.S.R.) describes the mini-fold preparative possibility for pyrroles from ketoximes and acetylenes, a reaction discovered by Trofimov and developed by him into a most important entry into pyrrole chemistry.Volume 51 should have been an ''Index Volume,'' and indeed the indices were already in an advanced stage, when serious illness in the indexer's immediate family prevented their inclusion in this volume. They will appear in a later volume.