4-Methyl-substituted 6-oxa-8α-analogs of steroid estrogens have been synthesized and the ¹H and ¹³C NMR signals of these compounds have been completely assigned. It is shown that introduction of a methyl group in position 4 of steroids of the given stereochemical series leads to the loss of uterotropic and hypertriglyceridemic effects of the modified compounds. Steroids with these properties may have promise for the creation of vectors for transport into target organs of estrogens of other classes of compounds and inhibitors of enzymes responsible for the metabolism of hormones.