NMR assignments for BYZX, M1 and M2.
The numbers in the first column correspond to those in Fig. 7. All of the signals were assigned with the help of 2D-NMR. The values of δH at position 8∼10 for BYZX are distinct from those for M1 and M2, due to the splitting signals resulting from C = C reduction. The carbonyl signal still remained (Position 19).