I. General Questions of Total Synthesis.- 1. Statement of the problem of total synthesis.- Classes of steroid compounds.- History of total steroid synthesis.- Prospects for total synthesis.- 2. Building up of the steroid skeleton.- Methods of introducing side chains.- Methods of forming and transforming the rings.- Diene synthesis.- 3. Formation of centers of asymmetry.- Sterochemistry of polycyclic systems.- Reactions for the formation of centers of asymmetry.- Electrophilic reactions with ketones.- Reduction with alkali metals.- Catalytic hydrogenation.- Isomerization of double bonds.- Stereochemistry of cyclization.- Methods of resolving racemates.- 4. Nomenclature of synthetic steroids.- II. Total Syntheses from AB, AC, and AD Fragments.- 1. Syntheses of the type AB ? C ? D.- Synthesis via C14 ketones with aromatic rings A and B.- Syntheses via C14 ketones with an aromatic ring A.- Syntheses from bicyclic ketones.- Syntheses via diacids.- 2. Syntheses of the type AB ? CD.- Condensations of aromatic dienes.- Condensations of nonaromatic dienes.- Syntheses of thiasteroids.- 3. Syntheses of the type AB ? D ? C.- Syntheses with the initial formation of the C8-C14 bond.- Syntheses with the initial formation of the C12-C13 bond.- Syntheses of azasteroids, oxasteroids, and thiasteroids.- 4. Syntheses of the type AC ? B ? D.- Syntheses via biphenyl derivatives.- Syntheses via diphenylethane derivatives.- 5. Syntheses of the type AD ? BC.- Syntheses via diacids.- Syntheses via diketones.- Syntheses via dienynes.- III. Total Syntheses from BC and BD Fragments.- 1. Syntheses of the type BC ? A ? D.- Syntheses of 11-deoxysteroids.- Syntheses of 11-hydroxy steroids.- 2. Syntheses of the type BC ? D ? A.- Syntheses via BCD intermediates with a five-membered ring D.- Syntheses via BCD intermediates with a six-membered ring D.- 3. Syntheses of the type BD ? C ? A.- IV. Total Syntheses from CD Fragments.- 1. Syntheses of the type CD ? A ? B.- Syntheses of estrogens and 19-norsteroids.- Syntheses of vitamin D derivatives.- Syntheses of azasteroids.- 2. Syntheses of the type CD ? B ? A.- Syntheses from 5-methoxy-2-tetralone.- Syntheses from 6 -methoxy-2 -tetralone.- Syntheses from nonaromatic CD fragments.- 3. Syntheses of the type CD ? BA.
Since the appearance of the Russian edition of this monograph (1967), the main tendencies of the development of total synfuesis have not changed. The accelerated accumulation of experimental material is continuing, mainly in the form of the improvement of already-existing synthesis schemes. The main new advance is the development of asymmetric syn theses with intermediates that have made it possible to avoid the main dis advantage of total synthesis - the formation of racemic final compounds. The most important work that has appeared since the appearance of the Russian edition is given in an Appendix to the book. Apart from this, only a very slight rearrangement of the material and of some of the schemes has been carried out for the American edition. A. A. Akhrem Yu. A. Titov Moscow, July 1968 v Preface to the Russian Edition Steroids are one of the most interesting and most widely distributed and, at the same time, one of the most structurally complex groups of natural compounds. In spite of this, the great theoretical and practical importance of steroids for biology and medicine has led to very intensive scientific research work on their synthesis. The numerous methods for obtaining steroids developed at the present time can be divided into four main groups: isolation from natural sources, microbiological synthesis, partial synthesis from natural raw material already containing the steroid skeleton, and, finally, total chemical synthesis from precursors of com paratively simple structure.
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