title: Ab Initio Study of Endo/Exo and Diastereofacial Selectivities in Diels-Alder Reactions between Chiral Butenolides and Cyclopentadiene.
abstract: Diels-Alder reactions of cyclopentadiene with crotonolactone and beta-angelica lactone have been studied using ab initio methods at the MP3/6-31G//RHF/3-21G and MP2/6-31G//RHF/6-31G levels. The transition states corresponding to the formation of different stereoisomers and diastereoisomers have been located. The results obtained show that the correct endo/exo selectivity is only obtained when polarization functions are included in the basis set. However, syn/antiselectivity is correctly described at all levels of calculation.
authors.affiliation: Departament de Química, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Spain.
authors.forename: Abdelouahid
authors.initials: A
authors.lastname: Sbai
authors.forename: Vicenç
authors.initials: V
authors.lastname: Vicenç Branchadell
authors.forename: Antonio
authors.initials: A
authors.lastname: Oliva