3339. Diploicin
Nomenclature
CAS number: 527-93-5
2,4,7,9-Tetrachloro-3-hydroxy-8-methoxy-1,6-dimethyl-11H-dibenzo[b,e][1,4]dioxepin-11-one; 3,5-dichloro-6-[(3,5-dichloro-6-hydroxy-4-methoxy-o-tolyl)oxy]-4,2-cresotic acid ε-lactone; 5,6′-dimethyl-2′,3-dihydroxy-4′-methoxy-2,3′,4,5′-tetrachloro-6-carboxydiphenyl
ether 2′,6-lactone. C16H10Cl4O5; mol wt 424.06.
C 45.32%, H 2.38%, Cl 33.44%, O 18.86%.
Description and references
Antibiotic isolated from the lichen Buellia canescens (Dicks.) De Not. [Diploicia canescens (Dicks.) Massal.], Lecideaceae: Zopf, Ann. 336, 58 (1904); Nolan, Sci. Proc. R. Dublin Soc. 21, 67 (1934); Nolan et al., Chem. Ind. (London) 1935, 577; Barry, Nature 158, 131 (1946). Structure: Nolan et al., Sci. Proc. R. Dublin Soc. 24, 319 (1948). Synthesis: Ollis, ibid. 27, 161 (1956); Brown et al., Proc. Chem. Soc. London 1960, 393; Hendrickson, Ramsay, Chem. Commun. 1968, 1101; Hendrickson et al., J. Am. Chem. Soc. 94, 6834 (1972); P. D. Djura et al., J. Chem. Soc. Perkin Trans. 1 1976, 147.
Properties
White needles from methanol, mp 233-234°. uv max: 270 nm (log ε 3.79).Derivative
Acetate.C18H12Cl4O6; mol wt 466.10.
C 46.38%, H 2.59%, Cl 30.43%, O 20.60%.