FID - Dual Methylene Group Transfer

NMR spectra were acquired on Bruker Avance 400 and Bruker Avance 600 spectrometers at room temperature; the chemical shifts d were measured in ppm with respect to solvent (1Н: CDCl3, δ = 7.26 ppm; DMSO-d6: δ = 2.50 ppm; 13C: CDCl3, δ = 77.2 ppm; DMSO-d6: δ = 39.5 ppm). Splitting patterns are designated as s, singlet; d, doublet; t, triplet; m, multiplet; dd, double doublet; ddd, double double doublet; dddd, double double double doublet. Coupling constants (J) are given in Hertz.