Reaction #81465

Reaction equation

triethylamine

adrenosterone

tert-butyldimethylsilyl trifluoromethanesulfonate

→

title compound

3-(tert-Butyldimethylsiloxy)androsta-3,5-diene-11,17-dione

Solvents

dichloromethane

Conditions

Workup

1. 1
   OtherThe dichloromethane was evaporated
2. 2
   workup.DISSOLUTIONthe residue redissolved in diethyl ether (100 ml)
3. 3
   workup.WAITto stand for 30 min
4. 4
   Otherafter which time an oil separated
5. 5
   OtherThe ether phase was decanted off the oil
6. 6
   Otherthe solvent evaporated

Procedure

To a solution of adrenosterone (6.0 g, 20 mmol) in dry, dichloromethane (120 ml) was added triethylamine (8.4 ml, 60 mmol) followed by tert-butyldimethylsilyl trifluoromethanesulfonate (5.0 ml, 22 mmol) and the mixture stirred at room temperature for 3 h. The dichloromethane was evaporated and the residue redissolved in diethyl ether (100 ml), then allowed to stand for 30 min, after which time an oil separated. The ether phase was decanted off the oil and the solvent evaporated to give the title compound which was used directly in step (b). IR νmax 1705, 1747 cm-1 ; 1H-NMR(CDCl3) inter alia δ0.12 (6H,s,Me2Si), 0.85 (3H,s,18-CH3), 0.92 (9H,s,tBuSi) 1.17(3H,s, 19-CH3), 4.73 (1H,dm, J 6.9Hz, 6-H), 5.36 (1H,m,4-H).

Source