Eight-Membered Rings With Two Heteroatoms 1,2

The chapter titled “Eight-membered Rings with two Heteroatoms 1,2” deals with heterocine rings with two heteroatoms in a 1,2 relationship, namely 1,2-diazocine, 2H-1,2-oxazocine, 2H-1,2-thiazocine, 1,2-dioxocin, 1,2-oxathiocin and 1,2-dithiocin. This article covers the literature from 2007 to 2019 and reports the chemistry of uncondensed derivatives, heterocines fused to carbocycles and heterocycles, as well as bridged heterocines. As usual, in the case that a particular section is not mentioned, it means that no chemistry has been reported. In this article, the “Biosynthesis” paragraph was additionally introduced, since in the latest years the contribution of Nature to the synthesis of diheterocines became important, especially for biologically active compounds. Following this approach, the natural sources will be analyzed, as well as the biosynthetic pathway whenever available. In this edition, as happened in the previous one, the interest in 1,2-heterocines has been driven by the pharmacological activity shown by several derivatives or some potentially important industrial applications.