Reduction of N-alkyl-3-sulfonylglutarimides with (1) sodium hydride and then with lithium aluminum hydride, or (2) sodium borohydride yielded two different types of regioselectively reduced hydroxypiperidinones which were further dehydrated to two pyridin-2-ones in the presence of boron trifluoride etherate. Cycloaddition and regioselective reduction were combined to synthesize 1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine and homobaclofen.