抄録
From the ethanolic extract of the seeds of Selinum Monnieri L. there were isolated osthol, bergapten, oroselone and a new coumarin compound, O_<21>H_<22>O_7, m.p.144-146°, [α]^<23>_D+106.7°(c 1.71 in benzene), [α]^<25>_D+84.8°(c 1.76 in pyridine) which was however shown identical with edultin (IV)a, m.p.136-142°, [α]^<11>_D+41.5°(c 26.8 in pyridine) recently isolated by Miteuhashi and Ito from the root of Angelica edulis Miyabe. Since (+)-tetrahydrooroselol (V)b, m.p.113.5-114.2°, [α]^<26>_D+68.0°(c 1.11 in chloroform) obtained by hydrogenolysis followed by saponification of edultin was found identical with the one prepared by Schmid et al. upon the same treatment of athamantin(IV)b, the same configuration at C_2, in both compounds was established. The acetate (V)a of (+)-tetrahydrooroselol was converted into (+)-hexahydrooroselone (+)-(VII), [α]^<25>_D+25.4°(c 1.02 in ethanol) by pyrolysis followed by hydrogenation of the resulted unsaturated compound (V1)a. The asymmetric center of (+)-(VII) was correlated with that of the side chain of rotenone as follows. Gattermann's formylation of (-)-(R)-dihydrotubanol (IX) gave the o-aldehyde (X)a. Heating with malonic acid, pyridine and aniline converted the aldehyde into the coumarin carboxylic acid (XI)a, m.p.188°, which was then decarboxylated to give the coumarin (XI)b, m.p.110-111°. (-)-Hexahydrooroselone (-)-(VII), m.p.106°,[α]^<20>_D-72.0°(c 1.23 in ethanol) prepared by catalytic hydrogenation of (XI)b was proved to be enantiomeric with the one obtained from edultin, indicating the(R)-configuration at C_2, in both edultin and athamantin. From its n.m.r. spectrum and thermal stability the cis relation of two hydrogens at C_2' and C_3' was deduced, suggesting the (R)-configuration at C_3, of edultin; probably the same would be true for athamantin.
