Photolysis of phenol derivatives

Horspool, William M (1964) Photolysis of phenol derivatives. PhD thesis, University of Glasgow.

Abstract

On irradiation di-p-t-butylphenyl carbonate has been shown to rearrange via a novel photo-catalysed double Fries reaction to yield 5,5-di-t-buty1-2,2'-dihydroxybenzophenone. The nsubstituted phenyl carbonate gave rise to 2,2,-dihydroxy and 2,4,-dihydroxybenzophonone. An indication that the mechanism of the reaction involved the formation and eventual rearrangement of the corresponding salicylate was obtained by isolation of 5-t-butylsalicylie acid and by the irradiation of phenyl salioylate. The photolysis of aryl formate esters has indicated that the primary decomposition process may well be intramolecular extrusion of carbon monoxide although there is some evidence that other dissociation processes are in operation. The irradiation of ?-naphthyls phenylp p-t-butylphenyl, 2,6-xyly1 and p-chloro-phenyl formates in oyolohexene gave rise to the corresponded; aryl cyclohevl ether. This photooatalysed addition to an olefin is not restricted to cyclohexene and irradiation of p-t-butylphenyl formate in pant-2-one and 2-methylpent-l-one gave rise to the respective ethers. Attempts were made to elucidate the mechanism by irradiation of 2-aIly1-4-t-butylphenyl formate and 2-(3,3-dimethylallyl)phenol. Both irradiations gave rise to good yields of the normal addition products. Another route to the generation of aryloxy radicals was investigated involving the synthesis and decomposition of peroxy compounds containing phonoxy ether groups. The synthesis and decomposition of Bis-phenoxypropionyl)peroxide has been carried out showing the generation of phenoxyethyl radicals. 0,0-t-Buty1-o-phenylmonopercarbonate has been synthesised and analysis of the mixture obtained from its decomposition in cyclohexene has shown the presence of phenyl cyciohoxyl ether. Methyl and ethyl 5-phenoxypenta-2,4-dienoate were synthesized, the former by condensation of phenol with methyl but-l-on-3-yne-1-oarboxylate, the latter by reuotion of carbethony-methylene-triphenyl aosphorane and 3-phenozyacrolein. Attempts to synthesise this system by reaction of 3-phonoxyacrolein with several compounds having an active methylene group were unsuccessful. Diels-Alder reactions were carried out on the ethyl ester to give l-ethyl 2v5-dimethylbenzeno-12v3-tricarboxylate with dimethylacetylenedicar.boxylate7 ethyl 1-naphthoate 171th benzyne and 3-oarbethoxy-6-phenoxy-1,2,6-tetrahydrophthalic anhydride and the corresponding acid with maleic allydride. Ethyl 2-methy1-5-phenoxypenta-204-dienoateg synthesised by reaction of 3-phenoxyacrolein and 1-carbethoxyethylidene-triphenyl phosphorane did not react with the above dienophiles.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: P L Pauson
• Keywords: Organic chemistry
• Date of Award: 1964
• Depositing User: Enlighten Team
• Unique ID: glathesis:1964-73334
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73334