Polycyclic Dihydroxy Compounds

Several dihydroxy compounds lying outside the preceding three classes are described in this section. Selective removal of the methoxymethyl group by treatment of 2-(1 -hydroxydecyl)-5-methoxy-1 -methoxymethoxynaphthalene and 

In continuation of studies on the aromatisation of synthetic polyketides, aryl C-glycosides in the 1,8-dihydroxynaphthalene series were obtained by an approach modelled on biomimetic lines. Thus diethyl 3-hydroxyglutarate (obtained from L-rhamnal) in tetrahydrofuran was added at O C under nitrogen to the lithium-sodium dianion of methyl acetoacetate (15 moles) in tetrahydrofuran/hexamethyl phosphoric triamide (1 1), the mixture was stirred at ambient temperature for 2.5 hours and after acidification the recovered crude diethyl 3,5,9,11-tetraoxo-tridecanedioate was refluxed for 2.5 hours in methanolic solution containing calcium acetate to afford the product shown in 40% yield as a single isomer, after 0-acylation, purification and O-deacylation (ref.61). ( MOM = methoxymethyl) 

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Boyland, E. and Levi, A.A. (1935) Metabolism of polycyclic compounds production of dihydroxy-dihydroanthracene from anthracene. Biochemical Journal, 29 (12), 2679-2683. 

The reactions reviewed in this group consist of oxidation and substitution in the ring for the benzenoid series and a number of sequences involving polycyclic compounds which contain 1,4-dihydroxy systems. 

Bicyclic, tricyclic and polycyclic compounds containing 1,4-dihydroxy systems undergo reactions not shown by the parent compound, 1,4-dihydroxybenzene. Naphthazarin together with boron trifluoride etherate in acetic acid following a... 

Fluoroalkyl chromone derivatives can be obtained from the base catalysed reaetion between 2,2-dihydropolyfluoroalkanoates and phenols. Initial loss of HF allows Michael addition of the phenol and subsequent cyclisation of the enol ether yields the heterocycle. m-Substituted phenols give the expected mixture of 5- and 7-substituted chromones, whilst dihydroxy aromatic compounds give polycyclic materials (94JFC263). In a more conventional approach Z-3-(aryloxy)-polyfluoroalkenoic adds, derived from Michael addition of phenols to polyfluoro-2-alkynoic acids, undergo intramolecular Friedel-Crafts acylation to 2-polyfluoro-alkylchromones (94JFC25). 

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