The stereochemical analysis of polymers derived from N,N-disubstituted acrylamides is usually difficult. The diad tacticity can be determined from the 1 H nuclear magnetic resonance (NMR) signals of the main-chain methylene groups. However, the splitting because of the configurational sequences is poor, even in 13 C NMR, which does not allow determination of the tacticity at the triad level. In contrast, the stereochemical analysis of polymers derived from N-monosubstituted acrylamides is easily conducted and the triad tacticity can be determined from the 13 C signals of the main-chain methine groups. Thus, stereochemical analysis of N,N-disubstituted polymers should be able to be conducted if the polymers are transformed into N-monosubstituted polymers with retention of the configurational sequence. Poly(N-tert-butyl-N-npropylacrylamide) was radically prepared, and de-tert-butylation was conducted by treatment with scandium triflate in a mixed solvent of CH 3 CN and 1,4-dioxane at 50, 80, and 110 C. 1 H NMR analysis of the resulting polymers indicated quantitative conversion after 72 hr, regardless of the temperature. 13 C NMR analysis of the transformed polymers confirmed that the configurational sequences were retained during the reaction. Thus, the triad stereochemical analysis of N,N-disubstituted polymers was successfully conducted by de-tert-butylation as a polymer reaction, followed by 13 C NMR analysis of the transformed polymers.