Synthesis of new symmetrical bis-steroidal pyrazine analogues from diosgenin

New symmetrical bis-steroidal pyrazine dimers that are cephalostatins/ritterazines analogues have been prepared easily from a cheap, readily available natural steroid (diosgenin). These dimers were obtained by classical, condensation of α-amino ketones in order to construct the pyrazine rings. The three dimers differ in the functionalized diosgenin: (25R)-5α,6β-dihydroxy-5α-spirosta-3-one, (25R)-4,5α-epoxy-5β-spirosta-3,6-dione and (25R)-5α-hydroxy-5α-spirosta-3,6-dione respectively.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights▶ Synthesis of symmetrical bis-steroidal pyrazine dimers as cephalostatins/ritterazines analogues. ▶ Diosgenin is implemented for the construction of these dimers. ▶ Classical condensation of a-amino ketones in order to obtain the pyrazine ring. ▶ The preparation of three dimers that differ in the functionalized diosgenin is described.