1,3-Oxazines and benzoxazines

This chapter deals with the reviews published in the past decade dealing with 1, 3-oxazines. It includes a survey by Steglich on the uses of 1, 3-oxazin-6-ones, as versatile intermediates in heterocyclic synthesis. A more general summary of the chemistry and uses of “oxazinones” covering the period 1976-1985 are presented by Zakhs and coworkers. More recent work on 1, 3-oxazines in general is reviewed by Yamamoto and Morita. Sections and subsections of the compounds are discussed in the order of decreasing number of double bonds in the ring. In this chapter the summaries begin with 2H- and end with 6H- types. Loctant for H (the indicated hydrogen) is given the lowest number, following the rules laid down in the International Union of Pure and Applied Chemistry, Nomenclature of Organic Compounds, 1979 edition, even though there are obvious difficulties with tautomerism, which can sometimes inter relate the above rankings. The carbonyl, thiocarbonyl and imino derivatives of each type are explained.