l-Proline-catalyzed direct intermolecular asymmetric aldol reactions of 1-phenylthiocycloalkyl carboxaldehydes with ketones. Easy access to spiro- and fused-cyclobutyl tetrahydrofurans and cyclopentanones.
[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.
Bernard
Angela M
AM
Dipartimento di Scienze Chimiche, Università degli studi di Cagliari, Complesso Universitario di Monserrato, S.S. 554, Bivio per Sestu, I-09042 Monserrato (Cagliari), Italy.
Frongia
Angelo
A
Guillot
Regis
R
Piras
Pier P
PP
Secci
Francesco
F
Spiga
Marco
M