Innovative reactor concepts show evidence to significantly improve the reaction performance in comparison to conventional reactor systems. To evaluate the reactor concepts, experimental investigation of the process behavior is indispensable. In this contribution, a reactor tandem comprising a repeatedly operated semibatch reactor (RSBR) followed by a continuously stirred tank reactor (CSTR) is analyzed for the hydroformylation of 1-dodecene. This reactor tandem was suggested by N. M. Kaiser et al. [Ind. Eng. Chem. Res. 2017, 56, 11507-11518] to increase the selectivity toward the linear aldehyde at high conversion levels of 1-dodecene. An additional degree of freedom is gained because of the combined utilization of a batchwise and continuously operated reactor. By using a dynamic process model for planning of the experiments, comparability is ensured with studies of a single CSTR from literature. The experiments confirm an increase in conversion and target product yield applying the RSBR + CSTR tandem, so that up to 90% selectivity is achieved with closed byproduct recycle.