... In summary, the N,N-dimethylformamide dimethyl acetal chemistry serves as a convenient link between 2- methyl-3 ... The organic layer was dried over sodium sulfate, filtered, and concentrated by i~otary evaporation. ... d 8.30 (br s, 1 H), 6.50-7.40 (m, 6 H), 6.17 (dd, 1 H, J = 16, 7 Hz ...