Four new tetrahydrofuranoid steroidal alkaloids, (+)-O6-buxafuranamine (1),(+)-2-dehydroxy-O2-buxafuranamine (2), (-)-O10-buxafuranamine (3) and (-)- 6-dehydroxy-O10-buxafuranamine (4) have been isolated from the leaves of Buxus hildebrandtii. These are the members of a new series of Buxus steroidal bases containing a tetrahydrofuran ring incorporated in their structures. The structures were established on the basis of extensive spectroscopic studies. Three new classes along with several more examples of the previously mentioned structural classes have been included in the rules which relates the structural features with the specific rotations. © 1992.