3.6.3. (*S*)-PGME Amide of **8** (**8**-18*S*)

Major isomer; brown amorphous solid; 1H NMR (CD3OD, 800 MHz) δ<sup>H</sup> 7.373–7.331 (5H, m, PGME-Ar), 5.429 (1H, s, PGME-H-1), 5.200 (1H, br d, *J* = 8.4 Hz, H-12), 4.799 (1H, td, *J* = 9.0, 4.1 Hz, H-11), 4.067 (1H, dd, *J* = 12.7, 5.2 Hz, H-2), 3.944 (1H, dd, *J* = 4.8, 1.3 Hz, H-8), 3.683 (3H, s, PGME-OMe), 2.674 (1H, d, *J* = 17.8 Hz H-7α), 2.572 (1H, m, H-4α), 2.465 (1H, m, H-17), 2.446 (1H, m, H-4β), 2.396 (1H, m, H-10α), 2.238 (1H, m, H-3α), 2.207 (1H, m, H-7β), 2.026 (1H, m, H-10β), 2.007 (2H, m, H-14), 1.823 (1H, m, H-3β), 1.668 (3H, d, *J* = 0.9 Hz, H-20), 1.596 (1H, m, H-16α), 1.462 (2H, m, H-15), 1.341 (1H, m, H-16β), 1.308 (3H, s, H-19), 1.048 (3H, d, *J* = 6.8 Hz, H-21); LRESIMS *m*/*z* 526.3 [M + H]+.
