title: An efficient and selective way to new highly functionalized coronands or spiro derivatives using ultrasonic irradiation.
abstract: A new, selective, straightforward and general method for preparation of highly functionalized coronands or spiro derivatives bearing 1,2-dihydroxyacetophenone unit, under conventional conditions and ultrasonic irradiation, is reported. The reaction setup involves only one step, acylation of an α-chloro-3,4-dihydroxyacetophenone with phthaloyl dichloride derivatives. 1,3- and 1,4-Phthaloyl dichloride derivatives leads to coronands only, while 1,2-phthaloyl dichlorides lead either to coronands or to spiro derivatives. A feasible explanation for the different behavior between conventional and ultrasound methods could be the different reaction mechanism involved in the two procedures: tetrahedral nucleophilic substitution under conventional conditions and radical substitution under ultrasound. Ultrasound induces a remarkable acceleration of the reactions (from days to minutes) and, most significantly, the yields are twice as high. A feasible explanation for the efficiency of the reactions under ultrasonic irradiation is presented.
authors: AlI Cuza University of Iasi, Organic Chemistry Department, Bd Carol 11, 700506 Iasi, Romania.
authors: Gheorghita
authors: G
authors: Zbancioc
authors: Ondina
authors: O
authors: Florea
authors: Peter G
authors: PG
authors: Jones
authors: Ionel I
authors: II
authors: Mangalagiu
mesh_terms: D000098:Acetophenones / Q000737:chemistry* / Q000528:radiation effects*; D047248:Crown Compounds / Q000737:chemistry* / Q000528:radiation effects*; D019220:High-Energy Shock Waves; D008956:Models, Chemical; D013010:Sonication / Q000379:methods*
chemical_list: D000098:Acetophenones; D047248:Crown Compounds; C019339:2,6-dihydroxyacetophenone