The use of H2O as an additive in SmI2-mediated reductive processes provides access to new transformations and previously inaccessible chemical space. The cyclisation of radicals derived from the selective mono-reduction of Meldrum’s acid derivatives was further investigated and the scope of the methodology expanded to cyclisation cascades. The first general methodology for the reduction of amide-type carbonyls under single electron transfer conditions was developed and applied to the mono-reduction of barbituric acid derivatives, providing an unprecedented direct access to the corresponding hemiaminals with a good degree of stereocontrol. The intermediate acyl-type radicals were in addition successfully exploited in stereoselective radical cyclisations. The hemiaminals derived from mono-reduction and cyclisation of barbituric acid derivatives have been exploited as N-acyliminium equivalents, affording hydrouracils with an excellent degree of regio- and stereoselectivity. Efforts towards the synthesis of the azulene framework of pseudolaric acid B using a model substrate are also described.