Complete Assignment of the1H and13C NMR Spectra of Steroidal Sapogenins: Smilagenin and Sarsasapogenin

Abstract

Ab initio proton and 13C NMR assignments for a stereoisomeric pair of 5β steroidal sapogenins, smilagenin (1) and sarsasapogenin (2), were accomplished using DEPT, COSY, TOCSY, HETCOR, HMQC, HMQC-TOCSY, HSQC-RELAY, HMBC and selective reverse INEPT techniques; the 13C NMR assignments for 2 were confirmed using 2D INADEQUATE experiments. This work corrects earlier 13C assignments for 1 and 2 proposed by Eggert and Djerassi. © 1997 John Wiley & Sons, Ltd.