TY  - JOUR
AU  - Rodríguez, C.M.
AU  - Martin, T.
AU  - Ramírez, M.A.
AU  - Martin, V.S.
T1  - Stereoselective Synthesis of Highly Substituted γ-Lactones by Diastereoselective Alkylation of α-(Benzenesulfonyl) Derivatives with Unusual Facial Selectivity
LA  - eng
PY  - 1994
SP  - 8081
EP  - 8091
T2  - Journal of Organic Chemistry
SN  - 1520-6904
VL  - 59
IS  - 26
AB  - The oxidation of α-(phenylthio) γ-lactones obtained by the base-induced cyclization of enantiomerically enriched γ-[(phenylthio)acyl]-α,β-unsaturated esters to sulfones in those cases where the α-carbon has an available proton and further basic alkylation led to an unexpected facial selectivity. The reaction proceeded smoothly with alkylating agents and unsaturated carbonyl compounds, but was unsuccessful when an addition to carbonyl derivatives was attempted. The alkylation reaction was performed over a wide range of substituted substrates in order to investigate the scope and limitations of the method and to have information about the possible origin of the selectivity. The application of the alkylation reaction was extended to the synthesis of bicyclic systems, including a cyclobutane with total stereochemical control. The presence of the α-(benzenesulfonyl) group is shown to be essential to achieve the facial selection. In order to rationalize the stereochemical results, extensive semiempirical calculations were performed. The use of MNDO and AM1 permits rationalization of the fact that the α-(benzenesulfonyl) group encumbers a diastereoface of the enolate generated in the ring, leading to the observed stereochemistry. © 1994, American Chemical Society. All rights reserved.
DO  - 10.1021/JO00105A027
UR  - https://portalciencia.ull.es/documentos/5ed31f6a2999526aa741257b
DP  - Dialnet - Portal de la Investigación
ER  -