Tamilmani, Venkatachalam Daul, Claude Lage Robles, Jaime Bochet, Christian G. Venuvanalingam, P. 2005-03-25 DFT investigations on the mechanism of Diels–Alder reactions of a hydroxy-ortho-quinodimethane with fumaric acid derivatives were performed to understand the origin of the syn or anti configuration of the adducts. The diene hydroxyl group and the dieneophile carboxyl group show hydrogen bonding in the transition state, significantly favouring the syn product. This reaction is poorly diastereoselective for R = CO₂Me (ratio syn/anti = 57:43) and significantly improved for R = CO₂H (ratio syn/anti = 71:29). The stereoselectivities are properly predicted from transition structures calculated at the B3LYP/6-31G(d) level. application/pdf https://folia.unifr.ch/global/documents/299574 https://folia.unifr.ch/documents/299574/files/1_bochet_hbs.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.cplett.2005.03.017 info:eu-repo/semantics/openAccess License undefined Chemical Physics Letters. - 2005, vol. 406, no. 4, p. 355-359 Diels-Alder DFT stereoselectivity transition states ortho-quinodimethane info:eu-repo/classification/udc/54 Hydrogen bond stabilization in Diels–Alder transition states: The cycloaddition of hydroxy-ortho-quinodimethane with fumaric acid and dimethylfumarate http://purl.org/coar/resource_type/c_6501