title: Ultrasound assisted reactions of steroid analogous of anticipated biological activities.
abstract: A new, fast, efficient and general method for preparation of steroid analogous of anticipated biological activity under ultrasound irradiation and classical heating is reported. The reaction pathway involves two steps: quaternization of phthalazine heterocycle followed by a 3+2 dipolar cycloaddition of cycloimmonium ylides to dienophiles. Under ultrasound the reaction time decreases substantially, the yields are higher, the reaction conditions are milder. A comparative study ultrasound verses classical heating has been done.
authors.affiliation: Al. I. Cuza University of Iasi, Organic and Biochemistry Department, Bd. Carol 11, 700506 Iasi, Romania.
authors.forename: Vasilichia
authors.initials: V
authors.lastname: Bejan
authors.forename: Costel
authors.initials: C
authors.lastname: Moldoveanu
authors.forename: Ionel I
authors.initials: II
authors.lastname: Mangalagiu
mesh_terms: D003500:Cyclization; D006358:Hot Temperature; D013256:Steroids / Q000138:chemical synthesis* / Q000737:chemistry; D014465:Ultrasonics
chemical_list: D013256:Steroids