Phosphorus-containing cyclic ester

Russian workers83 84 have synthesized a series of phosphorus-containing crowns utilizing O—P—O bonds in the macrocycle, i.e. cyclic phosphonate esters (7). One of these is claimed to have been prepared in 40% yield (equation 29). 

Several cyclic systems that contain phosphorus as a ring atom and which, structurally, are cyclic esters of phosphonothioic or phosphinothioic acids, are obtainable through... 

On the other hand, numerous examples are already known in which monomeric metaphosphoric esters are generated by thermolysis reactions. Most worthy of mention in this context is the gas phase pyrolysis of the cyclic phosphonate 150 which leads via a retro-Diels-Alder reaction to butadiene and monomeric methyl metaphosphate (151) 108,109, no). While most of the phosphorus appears as pyrophosphate and trimeric and polymeric metaphosphate, a low percentage (<5%) of products 152 and 153 is also found on condensation of the pyrolyzate in a cold trap containing diethylaniline or N,N,N, N,-tetraethyl-m-phenylene-diamine. The... 

There have been a number of developments worthy of special mention in chemistry involving pentaco-ordinated compounds and intermediates. These include reports of molecular mechanics calculations to study the hydrolysis of cyclic phosphorus esters, further detailed studies of the reactions of tervalent phosphorus compounds with acetylene carboxylates and the first synthesis of a pentaco-ordinated phosphorus compound containing a three-membered (phosphirene) ring. There has also been further elegant work in the area of phosphatrane chemistry. 

Another group of phosphorus- and oxygen-containing macrocycles are the cyclic phosphorus esters. For example, Robert developed a series of 12- and 18-membered rings, (8), and Picavet has synthesized the system based on cyclic phosphite esters, (9). French workers have prepared a series of macrocycles, containing two tertiary phosphine groups and two oxygen atoms (Scheme 1). The methylenic chains may be of two or three units. ... 

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