3,4-dihydro-2H-pyran → 21-Tetrahydropyranyl-11beta-hydroxy-1,4,16-pregnatriene-3,20-dione

Participants

Reaction Steps

To a solution of 11β,21-dihydroxy-1,4,16-pregnatriene-3,20-dione (200 mg, 0.58 mmole) in dichloromethane (40 ml) were added 2,3-dihydropyran (0.2 ml, 2.19 mmole) and anhydrous pyridinium tosylate (70 mg, 0.32 mmole). After stirring for 4 hours at room temperature, the reaction mixture was washed with water (100 ml) and evaporated to give a yellowish oil. This oil was placed on silica gel column and eluted with benzene ethyl acetate (2:1). Evaporating the solvent afforded pure white foam of 21-tetrahydropyranyl-11β-hydroxy-1,4,16-pregnatriene-3,20-dione (191 mg. 77.1%), 1H--NMR (CDCl3) δ 1.25 (s, 3H, 13--CH3), 1.49 (s, 3H, 10--CH3), 4.63-4.38 (m, 3H, 20--CH2 -- and 11--H), 4.68 (t, 1H, J=5 Hz, --O--CH--O--), 3.5, 3.85, 1.1 (m. pyranyl H), 6.01 (s, 1H, 4--H), 6.27(dd, 1H, J=10 and 2 Hz, 2--H), 6.73(m, 1H, 16--H), 7.31(d, 1H, J=10 Hz, 1--H).

Provenance & Evidence