title: Direct formation of the steroid nucleus by a nonenzymic biogenetic-like cyclization. Cyclization and proof of structure and configuration of products.
mesh_terms: D003500:Cyclization; D013058:Mass Spectrometry; D008961:Models, Structural; D009904:Optical Rotation; D011374:Progesterone / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013256:Steroids / Q000138:chemical synthesis; D013329:Structure-Activity Relationship
chemical_list: D013256:Steroids; D011374:Progesterone