title: An improved synthesis of 18-norandrost-4-ene-3,17-dione.
abstract: We describe the synthesis of 13 beta- and 13 alpha-H-18-nor-androst-4-ene-3,17-dione (1a and 1b) from 18-hydroxyprogesterone (18-->20) hemiketal, via the 18-acetoxy-17 beta-hydroxyandrost-4-en-3-one formed by a modified Baeyer-Villiger reaction. Saponification of 18-acetoxyandrost-4-ene-3,17-dione with sonication, then retroaldolization in the presence of a formaldehyde trap, methone, afforded the mixture of 1a and 1b with 80% yield in a "one-pot" procedure and at room temperature. This yield was greatly improved, compared with the already published procedure.
authors: Laboratoire de Chimie Organique Biologique, URA CNRS 493, Université Pierre et Marie Curie, Paris, France.
authors: E
authors: E
authors: Davioud
authors: P
authors: P
authors: Schambel
authors: A
authors: A
authors: Viger
authors: A
authors: A
authors: Marquet
mesh_terms: D006861:Hydrogen Peroxide; D006908:Hydroxyprogesterones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D009635:Norandrostanes / Q000138:chemical synthesis*; D013010:Sonication
chemical_list: D006908:Hydroxyprogesterones; D009635:Norandrostanes; C044510:18-hydroxyprogesterone; C080735:18-norandrost-4-ene-3,17-dione; D006861:Hydrogen Peroxide