David J. Calvert

Naphthalene tetrachlorides and related compounds. Part 10. The carbon-13 nuclear magnetic resonance spectra of some naphthalene tetrachlorides

Details of the carbon-13 n.m.r. spectra of four 1,2,3,4-tetrachlorotetralins (naphthalene tetrachlorides) and of three 1,2,3,4-tetrachloro-2-methyltetralins are presented. Chemical shifts of the signals attributable to the individual alicyclic and aromatic carbon atoms have been recorded and as far as possible identified by conventional methods; 1JC, H coupling constants have also been recorded. Several different types of 2JC, H and 3JC, H coupling constants have been identified from the details of the single resonance and partly decoupled high-resolution spectra. The results are discussed in relation to the known stereochemistry of these compounds.

13C nuclear magnetic resonance spectra of some bromo- and methyl-substituted cyclohexa-2,5-dienones

The 13C n.m.r. spectra of cyclohexa-2,5-dienones produced by bromination or nitration of a variety of methyl-substituted phenols are reported. Most of the signals have been assigned with the assistance of selective decoupling. Correlations of chemical shifts resulting from replacement of hydrogen by methyl and by bromine in the positions originally ortho and meta to the hydroxy group have been attempted. The effects resulting from changing the substituents at the 4-position from Br, Br to Me, Br to Me, NO2, and to Me, OH have also been analysed. Comparison is made with effects found in related systems. Single-resonance spectra have been used to determine coupling constants {J(1H, 13C)}, and these also are compared with cognate results.

Naphthalene tetrachlorides and related compounds. Part 11. trans-1,1,3,4-Tetrachlorotetralin-2-one, its hydrate, and related compounds

X-Ray crystallographic analysis of 1,1,3,4-tetrachlorotetralin-2,2-diol has shown that this compound is the trans-isomer, which can be reversibly dehydrated to give trans-1,1,3,4-tetrachlorotetralin-2-one of previously unknown configuration, produced nearly quantitatively by chlorination of 2-naphthol in acetic acid. The 1H and 13C spectra of these compounds are reported; most of the angular-dependent coupling constants accord with expectations, the value of 3J(13C-1, 1H-3) being low, probably because the coupling path includes a carbonyl carbon atom. The rather high value of 3J(H-3, H-4) is discussed. The properties of some related ketodichlorides and ketotetrachlorides are reported.

Naphthalene tetrachlorides and related compounds. Part 12. Influence of some 1-substituents on the course of chlorination of derivatives of 2-naphthol

The chlorinations of 1-methyl-2-naphthol, 1-bromo-2-naphthol,2,2′-dihydroxy-1,1′-dinaphthylemethane, and 6-t-butyl-2-naphthol with excess of chlorine in acetic acid give tetralin-2-ones analogous to that formed from 1-chloro-2-naphthol. 1,6-Di-t-butyl-2-naphthol, however, gives only 1,6-di-t-butyl-1,3-dichloro-1,2-dihydronaphthalene; 1-iodo-2-naphthol gives some 1,1,3,4-tetrachlorotetralin-2-one in acetic acid, whereas in chloroform it gives a mixture from which r,-1,c-2,t-3,t-4,5,7-hexachlorotetralin-6-ol was isolated. The structures of these products and the pathways leading to them are discussed.