Water → 21-Methylene-20(R)-methylpregn-4-en-3beta-ol
Reaction equation
[CH2:1]=[CH:2][C@@H:3]([CH3:24])[C@@H:4]1[C@:21]2([CH3:22])[C@H:7]([C@H:8]3[C@H:18]([CH2:19][CH2:20]2)[C@:16]2([CH3:17])[C:11](=[CH:12][C:13](=[O:23])[CH2:14][CH2:15]2)[CH2:10][CH2:9]3)[CH2:6][CH2:5]1.C(O[AlH-](OC(C)(C)C)OC(C)(C)C)(C)(C)C.[Li+].O.[OH-].[Na+]>C1COCC1>[CH2:1]=[CH:2][C@@H:3]([CH3:24])[C@@H:4]1[C@:21]2([CH3:22])[C@H:7]([C@H:8]3[C@H:18]([CH2:19][CH2:20]2)[C@:16]2([CH3:17])[C:11](=[CH:12][C@@H:13]([OH:23])[CH2:14][CH2:15]2)[CH2:10][CH2:9]3)[CH2:6][CH2:5]1Participants
6
Procedure
A suspension of 21-methylene-20(R)-methylpregn-4-en-3-one (5, 100.0 mg, 0.3063 mmol) and lithium tri-t-butoxyaluminohydride (319.4 mg, 1.256 mmol) in 5 mL of anh. THF was stirred under argon for 6 h, after which water (48 μL), 15% (w/w) sodium hydroxide (48 μL), and water (143 μL) were added. The mixture was filtered through diatomaceous earth and the residue was extracted four times with 5 mL aliquots of THF. Concentration of the combined filtrates under reduced pressure and two-fold recrystallization from aqueous ethanol gave white platelets (42.6 mg, 0.130 mmol, 42%), m.p. 121-123° C. TLC (25% ethyl acetate/hexanes on silica gel) shows major product at Rf 0.38 and minor product at Rf 0.43 (starting material Rf 0.50).
Workup
- filtrationThe mixture was filtered through diatomaceous earth
- extractionthe residue was extracted four times with 5 mL aliquots of THF
- customConcentration of the combined filtrates under reduced pressure and two-fold recrystallization from aqueous ethanol
- customgave white platelets (42.6 mg, 0.130 mmol, 42%), m.p. 121-123° C
Sources & evidence
- ORD record
- ord-f7f56e00feef4dd3bab3aa6f2bd7df21
- Source dataset
- uspto-grants-1999_11
- Patent number
- US05994333
Reaction notes
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