Isobutyryl chloride → 3alpha-Isobutyryloxy-17beta-methoxy-5beta-androstane
Reaction equation
[OH:1][C@@H:2]1[CH2:19][CH2:18][C@@:17]2([CH3:20])[C@H:4]([CH2:5][CH2:6][C@@H:7]3[C@@H:16]2[CH2:15][CH2:14][C@@:12]2([CH3:13])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[O:21][CH3:22])[CH2:3]1.[C:23](Cl)(=[O:27])[CH:24]([CH3:26])[CH3:25]>N1C=CC=CC=1.C(Cl)Cl>[C:23]([O:1][C@@H:2]1[CH2:19][CH2:18][C@@:17]2([CH3:20])[C@H:4]([CH2:5][CH2:6][C@@H:7]3[C@@H:16]2[CH2:15][CH2:14][C@@:12]2([CH3:13])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[O:21][CH3:22])[CH2:3]1)(=[O:27])[CH:24]([CH3:26])[CH3:25]Participants
Conditions
- Temperature
- 7.5 °C
Procedure
A solution of 3α-hydroxy-17β-methoxy-5β-androstane (250 mg, 0.82 mmol) in dry pyridine (2 mL) was treated with isobutyryl chloride (0.12 mL, 1.15 mmol), and N,N-dimethylaminopyridine (5 mg) at 5° C. After stirring the mixture at 5-10° C. for 1 hr the mixture was quenched with HCl solution (0.5N, 25 mL). The mixture was extracted with EtOAc. The organic layer was washed with dil. HCl, 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 hexane:acetone mixture (9:1) gave 3α-isobutyryloxy-17β-methoxy-5β-androstane (266 mg); mp 82-87° C.; TLC Rf (hexane:acetone 9:1)=0.6.
Workup
- customwas quenched with HCl solution (0.5N, 25 mL)
- extractionThe mixture was extracted with EtOAc
- washThe organic layer was washed with dil. HCl, water, and brine
- customAfter drying over anhyd
- filtrationMgSO4 the solution was filtered
- customevaporated
- customto yield the crude product
- additionpoured on a column of silica gel
- washElution with hexane
Sources & evidence
- ORD record
- ord-d0bf7c70a06c4727b271e5fb1610ad85
- Source dataset
- uspto-grants-1999_07
- Patent number
- US05925630
Reaction notes
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