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Organophosphorus Antioxidants. XII. Synthesis and N.M.R. Spectroscopy of Organophosphorus Antioxidants and Related Compounds The syntheses of various aliphatic, aromatic, sterically hindered, and cyclic organophosphorus compounds (phosphorous acid esters, ester chlorides and ester amides, hydrogen phosphites, phosphonates and phosphates) are reported, and general procedures for preparation are given. The compounds synthesized were investigated by means of 31P‐, 1H‐ and 13C‐n.m.r. spectroscopy, and the chemical shifts measured are listed.

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Organophosphorus Antioxidants. III. Kinetics and Mechanism of the Decomposition of Cumyl Hydroperoxide by Cyclic Phosphites The reaction mechanism of cyclic esters of phosphorous acids I to VIII with cumyl hydroperoxide has been studied kinetically by means of 31P n.m.r. spectroscopy, high performance liquid chromatography and iodometric titration. The five‐membered cyclic phosphites (I and II) react with cumyl hydroperoxide to give the corresponding phosphates (AI and AII) and cumyl alcohol. With more hydroperoxide or water they form the open chain phosphate esters (BI and BII) which decompose cumyl hydroperoxide catalytically giving phenol and acetone. Higher membered cyclic phosphites (III to VIII) react with cumyl hydroperoxide to give the corresponding phosphates and alcohol only. The mode of reaction depends on the hydrolysis behaviour of the cyclic phosphates (AI to A VIII). Only fivemembered cyclic phosphites which give easily hydrolyzable phosphates are able to decompose cumyl hydroperoxide catalytically. The nature of the exocyclic group in the phosphites has no influence on this behaviour. The kinetic parameters of the separate reaction steps are given. The ionic mechanism of hydroperoxide decomposition is accompanied by a homolytic one.

Organophosphorus Antioxidants. I. Kinetics and Mechanism of the Decomposition of Alkylhydroperoxides by o‐Phenylene Phosphites and Phosphates The reaction mechanism of 2‐(2, 6‐di‐tert‐butyl‐4‐methyl‐phenoxyl)‐1,3,2‐benzodioxaphosphole (1) with cumyl and t‐butyl hydroperoxide has been studied kinetically by means of 31P‐n.m.r. spectroscopy and high pressure liquid chromatography. 1 reacts with cumyl hydroperoxide to give the corresponding 2‐oxide (2) which with more hydroperoxide and/or water forms the open chained phosphate ester 5. This acidic phosphate decomposes hydroperoxide catalytically. The kinetic parameters of the separate reaction steps are given. The ionic mechanism of hydroperoxide decomposition is accompanied by a homolytic one in a minor proportion.