Copper-catalyzed 1,3-dipolar cycloaddition reaction of spirosolanederived azide for the preparation of modified solasodine alkaloid

Abstract

[Figure not available: see fulltext.] Modification of the steroidal alkaloid solasodine was performed by introduction of 1,2,3-triazolyl substituents at the С-6 atom of spirosolane ring system. The azidolysis of 5,6α-epoxysolasodine diacetate, formed as the major product during epoxidation of solasodine diacetate by the action of sodium azide in DMF in the presence of ammonium chloride, proceeded through the formation of 6β-azido-5α-hydroxysolasodine diacetate. The newly obtained azide was used in reactions with terminal alkynes in the presence of copper(I) bromide and N,N-diisopropylethylamine in DMF to synthesize the respective (22R,25R)-N,O-diacetyl-6β-[4-aryl-1,2,3-triazol-1-yl]-5α-hydroxyspirosolanes.