Quinone Methides Related to 1-Naphthol

This thesis contains three short reviews as follows: 1. Reaction of 1-naphthol with electrophiles 2. Formylation of 1-naphthol 3. Preparation methods and different types of reactions of quinone methides. Repetition of treatment of 1-naphthol with carbon disulphide and then dibromoethane gives the two isomeric quinonemethides (A) and (B) and not, as claimed earlier, exclusively the para isomer. The major product of this reaction is proved to be the ortho one by detailed analysis of its spectra and by reduction via a dihydroderivative to 2-methyl-1-naphthol which was prepared independently for comparison. The para isomer is present in very small amount but it can be isolated by chromatography and its structure confirmed spectroscopically. This thesis describes an investigation of a specific route to the para isomer. Several methods to formylate 1-naphthol were investigated. The Gattermann Adams reaction proved most effective. The dihydrophenol (c) was made from 4-formyl-1-naphthol but attempts using a wide range of oxidising agents failed to convert it to (A). The 2-bromoderivative also failed to undergo clean oxidation. 2-Methyl-naphthoquinonemethide (D) was prepared by the CS2 reaction and characterised, but 2-chloro- and 2-bromonaphthols failed to give the corresponding quinone methide. Changing the solvent of the original reaction of 1-naphthol gave the two isomers in the ratio (1:1). The two isomers were successfully isolated and fully characterised and their spectra is reported. The nmr spectra of (A) were found to be affected by the presence of acid

Cycloaddition Reaction of Ethyl Thioxoacetate and the Dienamine Derived from Pummerer's Ketone

The objective of this work is to study the regio- and stereochemistry of the cycloadducts obtained from the treatment of ethyl thioxoacetate and the dienamine derived from Pummerer's ketone