title: l-Proline-catalyzed direct intermolecular asymmetric aldol reactions of 1-phenylthiocycloalkyl carboxaldehydes with ketones. Easy access to spiro- and fused-cyclobutyl tetrahydrofurans and cyclopentanones.
abstract: [reaction: see text] Acid-catalyzed ring expansion of chiral cyclopropyl and cyclobutyl derivatives for the synthesis of carbo- and heterocyclic compounds is reported. The starting materials have been successfully prepared by l-proline-catalyzed direct asymmetric aldol reactions of 1-phenylthiocycloalkyl carboxaldehydes with ketones.
authors.affiliation: Dipartimento di Scienze Chimiche, Università degli studi di Cagliari, Complesso Universitario di Monserrato, S.S. 554, Bivio per Sestu, I-09042 Monserrato (Cagliari), Italy.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Bernard
authors.forename: Angelo
authors.initials: A
authors.lastname: Frongia
authors.forename: Regis
authors.initials: R
authors.lastname: Guillot
authors.forename: Pier P
authors.initials: PP
authors.lastname: Piras
authors.forename: Francesco
authors.initials: F
authors.lastname: Secci
authors.forename: Marco
authors.initials: M
authors.lastname: Spiga