'H-and* 3C-nmr assignments are reported for the steroidal alkaloids jervine, veratramine, cyclopamine, and cycloposine. Eleven of the jervine and at least four of the veratramine carbon resonances, reported earlier by others, have been reassigned.-and 13C-nmr spectra independentlyconfirm the structure of cycloposine as 3-glucosyl-11-deoxojervine. The lesser shielding shown by C-7 and C-8 of the jerveratrum alkaloids, compared to the choles-tane framework, suggests a general feature of the C-nor-D-homo skeleton.

The veratrum alkaloids occupy a position of prominence among steroidal alkaloids because some possess an unusual C-nor-D-homo skeleton (1, 2) and some are hypoten-sive (3), insecticidal (4), or teratogenic (5). 13C-nmr data have been reported for two members of the jerveratrum group (6) and for several ceveratrum alkaloids (7-9)· In par-ticular, the13C-nmr spectra of jervine (1) and veratramine (2) were of interest in our at-tempts to assign carbon resonances in the spectra of the mammalian teratogens cyc-lopamine (11-deoxojervine)(3) and cycloposine (3-glucosyl-11-deoxojervine)(4). Based upon 13C-nmr assignments reported (6) for jervine and veratramine, attempts to reconcile the structure of cyclopamine with itsspectrum showed several points of disag-reement. For example, an appropriate resonance for C-24 was not apparent in the cyc-lopamine spectrum and resonances assigned earlier to carbons 14, 16, and 20 of jervine appeared to be at variance with signals observed for cyclopamine. Inasmuch as the structure and stereochemistry of both jervine (10, 11) andcyclopamine (10-13) ap-peared to be firmly anchored on both physical and chemical grounds, the 13C-nmr