Dimethylsulfide-cuprous bromide complex

A solution of 24 g of 4-(N,N-dimethylaminoethoxy)bromobenzene was added dropwise over 45 min to magnesium in 90 ml of anhydrous tetrahydrofuran. 2 ml of 1,2-dibromoethane were added as catalyst. After the addition, the mixture was stirred at 25°C for one hour to obtain a solution of 0.7 M of 4-(N,N-dimethylaminoethoxy)-benzene magnesium bromide which was then added to a solution of 6.16 g of dimethylsulfide-cuprous bromide complex in 20 ml of tetrahydrofuran. The mixture was stirred at room temperature for 20 min and a solution of 3.7 g of 3,3-[l,2-(ethanediyl-bisoxy)]-5a,10a-epoxy-17a-prop-l-ynyl-8(9(1 L))-estrene-17p-ol in 50 ml of tetrahydrofuran was added thereto dropwise over a few minutes. The mixture was stirred under an inert atmosphere for one hour and was then poured into a solution of 15 g of ammonium chloride in 20 ml of iced water. The mixture was extracted with ether and the organic phase was washed with aqueous saturated sodium chloride solution, was dried and evaporated to dryness under reduced pressure. The 18.3 g of oil were chromatographed over silica gel and eluted with chloroform to obtain 4.5 g of 3,3-[l,2-ethanediyl-bisoxy]-lip-[4-(N,N-dimethylaminoethoxy)phenyl]-17a-(prop-l-ynyl)-89-estrene-5a,17p-diol with a specific rotation of [a]D20 =-44(+/-)1.5° (c = 1% in chloroform). 

---