A range of heterogeneous -SO3H functionalized catalysts including carbon and halloysite nanotubes, commercial K10 clay, Amberlyst-15 etc. was investigated for the first time using as a model the Prins-Ritter reaction of (−)-isopulegol with benzaldehyde and acetonitrile producing 4-amido derivatives of octahydro-2H-chromenes (as (S)- and (R)-diastereomers). A strong effect of water addition prior the reaction on the overall selectivity and the ratio of isomers in the case of heterogeneous and homogeneous (p-toluenesulfonic acid) catalysis was found for the first time. The yield of the (R)-diastereomer sharply increased with increasing amount of added water, while the S-isomer prevailed with a minimum amount of added water. Experimental results and DFT calculations clearly indicate a kinetic control for R-amide formation. Typically synthesis of 4-amidooctahydro-2H-chromenes requires subzero temperatures and toxic catalysts, which were avoided in the current work. Nevertheless, the yield of the desired products (up to 83 %) at 30 °C after water addition exceeded the values reported previously. Thus, adding water is a simple and a very effective method for controlling both the yield and stereoselectivity of the Prins-Ritter reaction products under mild conditions.