Dependence of the 1H NMR chemical shifts of ring F resonances on the orientation of the 27-methyl group of spirostane-type steroidal sapogenins.

A relationship between the 1H NMR chemical shifts of the ring F resonances and orientation of the H3-27 group has been derived for the establishment of 25R- and 25S-stereochemistry in spirostane type of steroidal sapogenins.