Ethylene Glycol → 3a-Methyl-6-[2-(2-methyl-[1,3]dioxolan-2-yl)-ethyl]-1,2,4,5,9a,9b-hexahydro-3aH-9-oxa-cyclopenta[a]naphthalene-3,7-dione

Participants

Reaction Steps

A solution of 13-methyl-1,8,11,12,13,14,15,16-octahydro-2H,6H-7-oxa-cyclopenta[a]phenanthrene-3,17-dione (1.55 g, 5.7 mmol), ethylene glycol (0.32 mL, 5.7 mmol) and pyridinium hydrochloride (0.66 g, 5.7 mmol) in benzene (28.5 mL) was refluxed with a Dean-Stark apparatus for 3 h. The reaction mixture was diluted with ethyl acetate (100 mL), washed with saturated sodium bisulfate solution, and dried with magnesium sulfate. Flash chromatography using 15% ethyl acetate in hexane yielded the title compound as a white solid.

Provenance & Evidence