(z)-7-{(1r,2s)-2-[(e)-(s)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-5-oxo-cyclopent-3-enyl}-hept-5-enoic acid methyl ester → (z)-7-{(1r,2r)-2-[(e)-(s)-5-(4-Bromo-5-methyl-thiophen-2-yl)-3-(tert-butyl-dimethyl-silanyloxy)-pent-1-enyl]-5-oxo-cyclopentyl}-hept-5-enoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 7 (170 mg, 0.28 mmol) in 4 mL toluene was added, by cannula, to a −40° C. mixture of hydrido(triphenylphosphine)copper(I) hexamer (300 mg, 0.15 mmol) in 4 mL toluene, rinsing with 0.5 mL toluene. The temperature was allowed to warm to 0° C. over 1 h and then was allowed to warm to room temperature. After a further 1 h, the reaction was quenched by addition of 15 mL saturated NH4Cl solution. The mixture was extracted with ethyl acetate (3×15 mL) and the combined ethyl acetate solution was dried (Na2SO4), filtered and evaporated. Purification by flash chromatography (8% ethyl acetate/hexanes→10%) gave the title ketone (150 mg, 0.25 mmol, 89%).

Provenance & Evidence