The syntheses of C-nor D-homosteroids

Abstract A certain number of alkaloids (veratramine, jervine and related compounds) contain a C-nor D-homosteroid skeleton. Compared with classical steroids these form, at the present moment, a less numerous and, above all, less thoroughly studied family of compounds. The present paper consists of two distinct parts. The first is a review of the recently discovered natural C-nor D-homosteroids, with a description of some pharmacological properties. In the second various studies on hemisyntheses and total syntheses of C-nor D-homosteroid compounds are analysed. This analysis shows that there is very little work published about the total synthesis of C-nor D-homosteroids and that, essentially, it can be put into two categories, that is, the synthesis of hydrochrysenes followed by contraction of the C-ring and the linear syntheses according to the DCBA and ABCD schemes.