Water → (3s,4Ar,10ar)-3-bromo-4a-ethyl-7-hydroxy-3,4,4a,9,10,10a-hexahydro-1h-phenanthren-2-one
Reaction equation
[Br-:1].[Br-].[Br-].[Br-].[C:5]1([N+](C)(C)C)[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.[C:15]1([N+](C)(C)C)[CH:20]=[CH:19][CH:18]=CC=1.[C:25]1([N+](C)(C)C)[CH:30]=CC=CC=1.[C:35]1([N+](C)(C)C)[CH:40]=CC=CC=1.[OH2:45].C([O:49][CH2:50][CH3:51])(=O)C>>[Br:1][C@H:40]1[CH2:35][C@:9]2([CH2:30][CH3:25])[C@H:8]([CH2:7][CH2:6][C:5]3[C:10]2=[CH:18][CH:19]=[C:20]([OH:45])[CH:15]=3)[CH2:51][C:50]1=[O:49]Participants
Conditions
- Temperature
- -78 °C
Procedure
To a solution of the title compound of Preparation 1f (5.4 grams, 22.1 mmol) in tetrahydrofuran (500 mL) at −78° C. was added phenyltrimethylammonium bromide tribromide (8.31 grams, 22.1 mmol) in portions. The mixture was allowed to stir at −78° C. for 1 hour and then allowed to slowly warm to 0° C. over 1.5 hours. After stirring at 0° C. for a further 3 hours, the mixture was poured into water and extracted twice with ethyl acetate. The combined extracts were dried (MgSO4) and concentrated to give an orange oil that was passed through a pad of silica gel washing with ethyl acetate. Concentration provided crude title product as an orange foam. 1H NMR (CDCl3) selected signals: δ 4.78 (dd, J=5.7, 13.5 Hz, 1H), 3.28 (dd, J=5.7, 13.0 Hz, 1H), 2.94-2.91 (m, 2H).
Workup
- temperatureto slowly warm to 0° C. over 1.5 hours
- stirringAfter stirring at 0° C. for a further 3 hours
- extractionextracted twice with ethyl acetate
- dry with materialThe combined extracts were dried (MgSO4)
- concentrationconcentrated
- customto give an orange oil that
- concentrationConcentration
Sources & evidence
- ORD record
- ord-913cc2157bbf4e7294cc74b4e7513b66
- Source dataset
- uspto-grants-2009_06
- Patent number
- US07553877B2
Reaction notes
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