Hooper, Joel F.James, Natalie C.Bozkurt, EsraAviyente, ViktoryaWhite, Jonathan M.Holland, Mareike C.Gilmour, RyanHolmes, Andrew B.Houk, K. N.2016-02-162016-02-162016-02-16201510.1021/acs.joc.5b02037https://infoscience.epfl.ch/handle/20.500.14299/123881WOS:000366877900018The intramolecular Diels-Alder reaction has been used as a powerful method to access the tricyclic core of the eunicellin natural products from a number of 9-membered-ring precursors. The endo/exo selectivity of this reaction can be controlled through a remarkable organocatalylic approach, employing MacMillan's imidazolidinone catalysts, although the mechanistic origin of this selectivity remains unclear. We present a combined experimental and density functional theory investigation, providing insight into the effects of medium-ring constraints on the organocatalyzed intramolecular Diels-Alder reaction to form the isobenzofuran core of the eunicellins.text::journal::journal article::research article