title: Calciferol and its relatives. XVII. Ring-A components for synthetic work on vitamin D3 and on model compounds.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D002762:Cholecalciferol / Q000138:chemical synthesis*; D003500:Cyclization; D004872:Ergocalciferols; D008722:Methods
chemical_list: D004872:Ergocalciferols; D002762:Cholecalciferol