(3R)-1-[(20S)-20-(Dimethylamino)-4-oxo-5α-pregnan-3β-yl]-3-isopropylazetidin-2-one

This alkaloid is the major base found in Pachysandra terminalis Sieb. et Zucco Like the other alkaloids present in this plant, it contains the pregnane skeleton. It is dextrorotatory with [α]D + 24° (CHCI 3). It has two keto groups in the molecule, one being present in a four-membered ring. Reduction with NaBH4 furnishes Pachystermine B (q.v.). The structure has been confirmed by the partial synthesis of the alkaloid.

Kikuchi, Uyeo., Tetrahedron Lett., 3473 (1965)
Kikuchi, Uyeo., Chem. Pharm. Bull., 15, 549 (1967)
Partial synthesis:
Kikuchi et al., Tetrahedron Lett., 909 (1968)