title: Synthesis of 12-mono- and di-substituted 8-aza-11-oxasteroids.
abstract: The synthesis of unsaturated derivatives of 8-aza-11-oxa-17-oxo-gonane and D-homo-gonane carrying one or two functional substituents at C-12 is reported. The key step for the construction of the heterosteroid skeleton was the cyclocondensation reaction of aldol adducts 1, derived from 1,3-cycloalkanediones and diethyl 2-oxo-malonate, with tosyl chloride and isoquinoline.
mesh_terms: D001378:Azasteroids / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D013260:Steroids, Heterocyclic / Q000138:chemical synthesis*
chemical_list: D001378:Azasteroids; D013260:Steroids, Heterocyclic