3 94 3h s och 3 6 92 1h s arh 6 99 1h arh 8 02 1h d arh 8 11 1h d arh 8 41 1h d arh 8 91 1h s arh the compound from step e 5 2 g 19 mmol ethylene glycol 4 4 g 71 mmol and a catalytic amount of p toluenesulfonic acid 0 2 g were dissolved in benzene 300 ml and refluxed for 28 h the solvent was removed and the crude product chromatographed on silica gel with hexane ethyl acetate 2 1 to yield 3 6 g 60 of the title compound 1 h nmr 400 mhz cdcl 3 u03b4 h 1 75 3h s ch 3 3 82 2h t och 2 3 91 3h s och 3 4 10 2h t och 2 6 93 1h s arh 6 98 1h d arh 7 47 3h m arh 8 04 1h s arh effectiveness of 3 methoxy 8 2 methyl 1 3 dioxolane 2 yl benzo c chromen 6 one against endothelial cells and epithelial cancer cell lines those skilled in the art will appreciate that several acceptable cell proliferation assays are known and available for demonstrating the activity of the compounds of the present invention the proliferation of endothelial cells is an important step in the process of blood vessel formation therefore.