Chapter 56 - Compounds with Larger Heterocyclic Rings: Compounds with Rings of More than Eight Atoms

Abstract

Publisher Summary This chapter discusses the nine-membered and ten-membered ring compounds along with compounds containing rings with more than ten atoms. Nine-membered ring compounds containing oxygen comprise of oxonins, dioxonins, and ring compounds with three or more atoms in the ring. Thionin and Thionane are examples of nine-membered ring compounds containing sulfur. Nine-membered ring compounds containing nitrogen are subdivided into rings containing one nitrogen atom such as Azonine and rings containing more than one nitrogen atom such as Trans-4,5,6,7,8,9-hexahydro-3H-1,2-diazonine. Ten-membered ring compounds containing oxygen, sulfur, selenium or nitrogen with one, two or more heteroatoms in the ring are also covered. Certain macrocycles containing heteroatoms, such as the heteroannulenes, the macrocyclic polyethers and the cyclam polydentate ligands, have acquired a chemical interest in their own right, and new specific routes have been sought for their synthesis. The high dilution technique, which denies the activated substrate access to others of its kind and so favors intramolecular reaction (cyclization) over intermolecular polymerization, has been as successful in the synthesis of heterocycles as in its earlier application to alicyclic systems. Rings with more than ten atoms are examined in the context of lactones, cyclic esters, diol carbonates and anhydrides, cyclic ethers, macrocyclic polyethers, and macrolide antibiotics.