3.5.4. (*R*)-MTPA Ester of **8** (**8**-2*R*)

White amorphous solid; 1H NMR (CD3OD, 800 MHz) δ<sup>H</sup> 7.671–7.659 (2H, m, MTPA-Ar), 7.422–7.408 (3H, m, MTPA-Ar), 5.611 (1H, dd, *J* = 12.8, 5.3 Hz, H-2), 5.133 (1H, br d, *J* = 8.6 Hz, H-12), 4.800 (1H, td, *J* = 9.0, 3.9 Hz, H-11), 3.973 (1H, d, *J* = 4.5 Hz, H-8), 3.655 (3H, s, MTPA-OMe), 3.603 (3H, s, H-22), 2.705 (1H, m, H-4α), 2.682 (1H, dd, *J* = 17.9, 1.2 Hz, H-7α), 2.480 (1H, d, *J* = 17.2 Hz, H-4β), 2.428 (1H, m, H-17), 2.409 (1H, m, H-10α), 2.243 (1H, m, H-7β), 2.165 (1H, m, H-3α), 2.067 (1H, dd, *J* = 12.4, 5.3 Hz, H-3β), 2.017 (1H, dd, *J* = 13.7, 3.9 Hz, H-10β), 1.956 (2H, m, H-14), 1.634 (3H, s, H-20), 1.555 (1H, m, H-16α), 1.368 (2H, m, H-15), 1.359 (1H, m, H-16β), 1.340 (3H, s, H-19), 1.082 (3H, d, *J* = 7.0 Hz, H-21); LRESIMS *m*/*z* 609.2 [M + H]+.
