1,2-Dibromoethene → 3beta-Ethynyl-3alpha-hydroxy-17beta-methoxy-5beta-androstane

Temperature

-78 °C

A solution of 1,2-dibromoethylene (1.6 mL, 3.7 g, 19.71 mmol) in dry THF (10 mL) was treated with n-BuLi (16.4 mL, 2.4M in THF, 39.4 mmol) at −75° C. After stirring the mixture at −78° C. for 0.25 hr, a solution of 17β-methoxy-5β-androstan-3-one (2 g, 6.57 mmol) in THF (20 mL) was added and the mixture was stirred at −78° C. for 15 min. The cooling bath was then removed and the mixture was quenched with NH4Cl solution (3 mL). The solvents were removed and the residue was extracted with EtOAc. The organic layer was washed with water, and brine. After drying over anhyd. MgSO4 the solution was filtered and evaporated to yield the crude product. This crude product was then dissolved in a small amount of CH2Cl2 and poured on a column of silica gel. Elution with toluene:acetone mixture (95:5) gave 3β-ethynyl-3α-hydroxy-17β-methoxy-5β-androstane (1.70 g) as a colorless solid; mp 62-65° C.; TLC Rf (toluene:acetone 95:5)=0.23.

1. stirringthe mixture was stirred at −78° C. for 15 min
2. customThe cooling bath was then removed
3. customthe mixture was quenched with NH4Cl solution (3 mL)
4. customThe solvents were removed
5. extractionthe residue was extracted with EtOAc
6. washThe organic layer was washed with water, and brine
7. customAfter drying over anhyd
8. filtrationMgSO4 the solution was filtered
9. customevaporated
10. customto yield the crude product
11. additionpoured on a column of silica gel
12. washElution with toluene

ORD record

ord-5ddd73292fc848ba84b29dd5661ffe90

Source dataset

uspto-grants-2004_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06780853B1