Chapter 54 - Compounds with seven-membered and larger rings containing one or more atoms of unusual hetero elements together with nitrogen or elements of group VI

Abstract

Publisher Summary This chapter discusses the compounds with seven-membered and larger rings containing one or more atoms of unusual hetero elements together with nitrogen or elements of group VI. 1, 2-Oxeborepanes are prepared by the alkaline hydrolysis and cyclization of the corresponding e-bromoalkylboric acids and their acid halides. A number of cyclic compounds of similar structure containing boron and oxygen are also prepared. Two heterocycles containing aluminum or boron and nitrogen are prepared. Silathiacyclooctane is prepared by the photochemical reaction of hydrogen sulfide with diallyldimethylsilane. The cyclic acetals are produced from carbonyl compounds and silicon oxygen containing heterocycles with the substituents and conditions. Compounds of similar structure are prepared by the reaction of dihydroxy aromatic compounds with various silanes. Two methods are available for the preparation of the cyclic silicon compound 7,7-dimethyl-3-thia-7-sila-7-heptanolide. The silacrown ethers are prepared by transesterification of alkoxysilanes with polyethylene glycols; these are generally colorless, odorless liquids of moderate viscosity. The reaction involves a siloxycarbene intermediate, which is then trapped by a second acylsilane molecule. The tricyclic compounds when added to ammonia give the dibenzoazaphosphepines. A cyclo Mannich reaction between primary amines and alkyl or aryl bishydroxymethylophosphines gives the 1,5-diaza-2,7-diphosphacyclooctanes.