3,17β-Dihydroxy-6-oxaestra-1,3,5(10),7-tetraen and related steroidal compounds have been synthesized in high yield via condensation of 7-methoxy-4-vinyl coumarin and 2-methyl-1,3-pentanedione. The approximate uterotrophic activity of the synthetic compounds relative to 17β-estradiol has been determined.