8-Hydroxy-6-methoxy-7-(3-methylbut-2-enyloxy)coumarin (capensine)

Abstract

The title coumarin derivative, C15H16O5, was isolated from the roots of Sophora japonica. The coumarin (2H-chromen-2-one) fragment is almost planar, with an r.m.s. deviation of 0.0356 Å. The carbon atom of the methoxy substituent is coplanar with the benzopyran oxa-heterocycle. The 3-methylbut-2-enyloxy group is disordered over two sets of sites with occupation factors of 0.920 (3) and 0.080 (3). In the crystal, molecules are linked by O—H...O and C—H...O hydrogen bonds into chains propagating along the [101] direction.