Synthesis of “glycospirostanes” via ring-closing metathesis

Syntheses of “glycospirostanes” from 3β-hydroxy-23,24-dinor-5α-cholano-22,16-lactone and 3α-hydroxy-23,24-dinor-5β-cholano-22,16-lactone were performed. The key step of these syntheses was ring-closing metathesis of the corresponding C,O-diallyl derivative. Further elaboration of the six-membered ring F consisted of allylic hydroxylation with SeO2 followed by OsO4 dihydroxylation of the C24–C25 double bond. The obtained final products proved to be simultaneously O- and C-l-arabinopyranosides.