Synthesis Of Osw-1 Analogues

How to utilize rationally some resource compounds to the synthesis of useful or potential useful molecule is one main task of our research group. Based on the reaseach results of rational utilization of the abundant steroidal sapogenins, my Master's dissertation work mainly focused on study of the syntheses of OSW-1 analogues such as 22-deoxy-OSW-1 and 12-hydroxy-dihydro-OSW-1. My dissertation presented three: main research results: 1, The Synthesis of 22-deoxy-OSW-l by utilizing the install skeletone of diosgenin was realized. Starting from D-xylose and L-arabinose, disaccharide trichoroactimidate segment (compound 43) of 22-deoxy-OSW-l and 12-hydroxy- dihydro-OSW-1 was synthesized in 13 steps reactions according to reported methods. Protection of the 3-OH of diosgenin with benzyl ether and subject to reduction reaction with Zinc and hydrochloric acid it was transformed into the 160, 26-dihydoxycholasterol 4. Removal of the 26-OH in compound 4 and subsequently oxidation of its 16-OH provided 16-oxo-cholasterol 7. The enol acetate of 16-oxo-cholasterol produced in situ reacted with Davis oxidation reagent¹² to result in stereoselective formation of 17α-hydroxy-16-oxo-cholasterol 9. The stereoselective reduction of compound 9 with LiAlH₄ at -78℃ provided the requested 22-deoxy -OSW-1 aglycone, 16β, 17α-dihydroxycholasterol 10. The glycosidation of...