We recognised that thiophene S,S-dioxides (TDOs) could address such limitations, as these heterocycles are in many ways 'ideal' diene substrates for IEDDA reactions. In contrast to oxadiazoles and other well-explored IEDDA substrates such as pyrones and tetrazines, TDOs are non-aromatic and therefore exhibit enhanced reactivity, while retaining the benefits of electron deficiency, an intrinsically s-cis constrained diene, and a powerful entropic driving force that renders the cycloaddition irreversible (namely, loss of SO2 through cheletropic extrusion). The deployment of TDOs in target-oriented synthesis remains surprisingly rare , but encouraged by our recent study in the context of the illudalane sesquiterpenes, we contemplated their application in the construction of the Strychnos alkaloids. Deviating from previous examples where TDOs have been used in the de novo construction of polysubstituted benzenes , we questioned whether these underexploited dienes could also be used to assemble the non-aromatic carbocyclic Strychnos core. No asymmetric TDO cycloadditions have been described to date, and we further considered whether we might not only use these easy-to-access heterocycles in a concise synthesis of a number of the Strychnos alkaloids, but also simultaneously develop the first asymmetric cycloadditions of TDOs, which would render this collective synthesis enantioselective.