Radiclonic acid, isolated from the mycelial extracts of an unidentified fungus 489-7 as a root growth-promoter, is a hydroxydienoic acid: In the present paper, structure I is assigned to 2 radiclonic acid.
Radiclonic acid, C23H4C05, gave a dimethyl ester(II);UV hz$l:250 (B 9900), 232(C 9600) nm, IR vzz$:1735, 1725 cm-$ NMR 6CDC1s:6.07(1H, b.s), 5.13(1H, b.d, J=lO Hz), 3.68, 3.63(each 3H, s), 3.47(2H, d, J=5 Hz), 3*2(4H, m), 1.66(JH, cl, J=c,z. 1 Hz);its acetate(III), NMR bCDC13:3.93(2H, cl, J=5 Hz), 2?.04(3H, s): II was hydrogenated on 5% Pa-C in ethanol to yield an n,G-unsaturated ester(IV)3;UV h~~~H:221(h 13000) nm, IR vz",$: 1737, 1723 cm-t NMR 6CDCl 3:5.63(lH, a, J=lO.5 Hz), MS m/e:426(M+). Data presented so far define the partial structure of a dienoic acid chromophore and functional groups in radiclonic acid(A).
Ozonolysis of III afforded a ketone(V) and an aldehyde(V1) as major products;V, IR vEzAr:1734 cm-t NMR 6"14 :3.83, 3.66(each 3H, s), 3.4-2.5 (3H, m), 1.21(3H, a, J=7 Hz), MS m/e:188(M+), 170, 151, 129, 101, 69, 59, VI, NMR 6CDC1 5:9.63(1H, d, J=2 Hz), 3.97(2H, d, J=5 Hz), 2.55(1H, m), 2.05 (3H, s). V was identified with 4-methyl-2-oxo-glutaric acid dimethyl 4 ester which was derived from 4-methyl-2-oxy-glutaric acid. Oxidation of VI with Jones reagent, followed by methylation with diazomethane, gave a methyl ester(VlI), IR vzz$+:1739 cm-t MS m/e:jOC(M+), 257, 240. tixtensive spin-decoupling experiments on VII with a NMR shift reagent Eu(DPM)3 allowed reasonable formulation for the structure of VII. In the