Phloroglucinol reaction with formaldehyde

It is interesting to note that while -CH2-O-CH2- ether bridged compounds have been isolated for the phenol-formaldehyde [24] reaction, their existence for fast-reacting phenols such as resorcinol and phloroglucinol has been postulated, but they have not been isolated, as these two phenols have always been considered too reactive with formaldehyde. They are detected by a surge in the concentration of formaldehyde observed in kinetic curves due to methylene ether bridge decomposition [19]. 

Phloroglucinol, according to Boehm , does not condense with formaldehyde at room temperature in the absence of added catalysts "When hydrochloric or sulfuric acid is added to the reaction mixture, a small quantitj of symmetrical hexahydroxydiphenylmethane (m.p 225 C) is formed, together with more complicated products. These products of further condensation are apparently" nuclear polymethylene derivatives iince on reduction of the crude acid condensation product with zinc dust and caustic soda, moncH, di- and tri-methy-lphloroglucinol as well as pbloro-... 

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