Shafiee A, Vossoghi M, Savabi F, Vlahov R, Tarpanov V, Boshkova-Ljapova M, Milenkov B, Stoilova V, Vlahov J, Snatzke G
Steroids. 1983 Mar;41(3):291-307. doi: 10.1016/0039-128x(83)90100-9.
Several esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) with carboxylic acids containing a cyclopropyl or cyclobutyl ring have been synthesized and the stereochemistries of the side-chains determined.