Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

A Collatolic acid

The best known depsidones are physodic acid, lobaric acid, norlobaridone, grayanic acid, alectoronic acid, diploicin, 4-0-methylphysodic acid, a-collatolic acid, lividic acid and variolaric acid. [Pg.10]

Elix, Ferguson, and Sargent (727) have studied the tautomerism of alectoronic acid (377), a-collatolic acid (382) and related depsides. The n.m.r. spectrum of alectoronic acid (Scheme 48) at ambient temperature exhibited a sharp two proton signal (8 4.06) due to the benzylic methylene protons of the A-ring side chain and a broad two proton signal (4.05 — 3.10) due to the protons H and Hg. At — 40 " C the signal for and Hg appeared... [Pg.183]

Methylphysodone (117) was isolated from Pseudevernia fur-furacea (339). 3-Alectoronic acid (118) and P-collatolic acid (119) are diphenyl ethers from Asahinea chrysantha (476) and A. scholanderi (476, 672) and exhibit an equilibrium between the keto-acid and lactol tautomers. 2" -0-Ethyl-P-alectoronic acid (120) from Alectoria sarmen-tosa (327) is probably an artefact formed during extraction by reaction of P-alectoronic acid with ethanol. [Pg.80]

See other pages where A Collatolic acid is mentioned: [Pg.113]    [Pg.114]    [Pg.317]    [Pg.182]    [Pg.186]    [Pg.186]    [Pg.183]    [Pg.510]    [Pg.227]    [Pg.113]    [Pg.114]    [Pg.317]    [Pg.182]    [Pg.186]    [Pg.186]    [Pg.183]    [Pg.510]    [Pg.227]    [Pg.392]   
See also in sourсe #XX -- [ Pg.317 ]

See also in sourсe #XX -- [ Pg.183 ]

See also in sourсe #XX -- [ Pg.510 ]

See also in sourсe #XX -- [ Pg.227 ]



SEARCH



© 2024 chempedia.info