Cesium carbonate → (5R)-5-[(E)-2-{5-[(1E)-4-{[tert-butyl(dimethyl)silyl]oxy}but-1-en-1-yl]-6-methoxypyridin-2-yl}-2-(4-tert-butylphenyl)ethenyl]-1-(2,4-dimethoxybenzyl)pyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

trans-4-(tert-Butyldimethylsiloxy)-1-buten-1-ylboronic acid pinacol ester (296 mg), tris(dibenzylideneacetone)dipalladium(0) (48 mg), tri(2-furyl)phosphine (73 mg) and cesium carbonate (354 mg) were added to a solution of (5R)-5-[(E)-2-(5-bromo-6-methoxypyridin-2-yl)-2-(4-tert-butylphenyl)ethenyl]-1-(2,4-dimethoxybenzyl)pyrrolidin-2-one obtained in Reference Example 4-42(1) (300 mg) in 1,4-dioxane (3 mL)-water (1 mL), and the mixture was stirred at an external temperature of 65° C. for three hours. The reaction solution was left to cool, diluted with ethyl acetate and filtered through celite. The filtrate was washed with brine and dried over sodium sulfate. After filtration, the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=9:1→3:2) to give (5R)-5-[(E)-2-{5-[(1E)-4-{[tert-butyl(dimethyl)silyl]oxy}but-1-en-1-yl]-6-methoxypyridin-2-yl}-2-(4-tert-butylphenyl)ethenyl]-1-(2,4-dimethoxybenzyl)pyrrolidin-2-one as a yellow oil (399 mg, 100%).

Provenance & Evidence