| Title:  Filicinic Acid CAS Registry Number:  2065-00-1 CAS Name:  3,5-Dihydroxy-4,4-dimethyl-2,5-cyclohexadien-1-one Additional Names:  1,1-dimethylcyclohexane-2,4,6-trione;  gem-dimethylphloroglucinol;  filicinsäure (German) Molecular Formula:  C8H10O3 Molecular Weight:  154.16 Percent Composition:  C 62.33%, H 6.54%, O 31.14% Literature References:  Isolated from male fern and by hydrolytic decompn of filixic acid or aspidin:  Boehm, Ann. 302, 171 (1898); 329, 321 (1903).  Synthesis:  Robertson, Sandrock, J. Chem. Soc. 1933, 1617; Angus et al., Chem. Ind. (London) 1954, 546; Inagaki et al., J. Pharm. Soc. Jpn. 76, 1258 (1956); Hoefer, Riedl, Angew. Chem. 74, 501 (1962); eidem, Ann. 656, 127 (1962). Properties:  Prisms from water or benzene, mp 214-215° (dec).  pK 5.8.  Practically insol in water, petr ether.  Sol in 70 parts boiling water, 10 parts boiling alcohol; sparingly sol in ether, benzene, glacial acetic acid.  Reduces Tollen's reagent. Melting point:  mp 214-215° (dec) pKa:  pK 5.8   Derivative Type:  3,5-Diacetylfilicinic acid  Molecular Formula:  C12H14O5 Molecular Weight:  238.24 Percent Composition:  C 60.50%, H 5.92%, O 33.58% Properties:  Crystals from methanol, mp 65-66°.  pK 5.0.  Sol in cold methanol, benzene, ether; slightly sol in hot water. Melting point:  mp 65-66° pKa:  pK 5.0   |