title: Observation of neighboring ortho-hydroxyl group participation in organocatalytic asymmetric sequential Michael-lactonization reactions: synthesis of highly substituted chiral spirodihydrocoumarins.
abstract: A general approach to asymmetric synthesis of highly substituted spirodihydrocoumarins with a quaternary stereocenter was achieved through neighboring ortho-hydroxyl group induced sequential Michael-lactonization reactions on 2-(2-nitrovinyl)phenols with alkyl cyclopentanone-2-carboxylates in the presence of a catalytic amount of quinine-NH-thiourea followed by p-TSA.
authors.affiliation: School of Chemistry, University of Hyderabad, Hyderabad-500 046, India. ramsc@uohyd.ernet.in
authors.forename: Dhevalapally B
authors.initials: DB
authors.lastname: Ramachary
authors.forename: R
authors.initials: R
authors.lastname: Madhavachary
authors.forename: M Shiva
authors.initials: MS
authors.lastname: Prasad
mesh_terms: D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003374:Coumarins; D006878:Hydroxides; D007783:Lactones; C031356:hydroxide ion