Chapter 2 - Unsaturated Acyclic Hydrocarbons

Abstract

Publisher Summary This chapter reviews the acyclic hydrocarbons that have one or more double or triple bonds in the molecule, which are considered in the following groups: hydrocarbons, CnH2n; hydrocarbons with two or more double bonds; acetylenes, CnH2n-2; hydrocarbons with two or more triple bonds; and hydrocarbons with both double and triple bonds. Owing to their ability to undergo numerous addition reactions, the unsaturated hydrocarbons have a much more extensive chemistry than the paraffin. The analysis of general methods of preparation, properties, and typical reactions of the olefins makes it evident why they are among the most versatile raw materials of the chemical industry. A similar approach is adopted for the study of hydrocarbons containing several double bonds, such as allenes and cumulenes, conjugated dienes, conjugated trienes, and polyenes. The acetylenes are isomeric with the corresponding dienes, and indeed acetylenes, allenes, and conjugated dienes are to some extent interconvertible by prototropic rearrangement. Hydrocarbons with more than one triple bond, such as conjugated diacetylenes and polyacetytenes, and hydrocarbons with both double and triple bonds, such as alkenynes, alkenediynes, aIkadienynes, and so on are also described in this chapter on the basis of general methods of preparation, properties, and typical reactions.