Toluene → 4(S)-t-Butyloxycarbonylamino-5-cyclohexyl-3(R,S)hydroxy-1-pentene
Reaction equation
C[O:2][C:3](=O)[C@H:4](C)[N:5]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])C1CCCCC1.[H-].C([Al+]CC(C)C)C(C)C.[CH:31]([Mg]Br)=[CH2:32].[C:35]1([CH3:41])[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1>>[C:15]([O:14][C:12]([NH:5][C@@H:4]([CH2:41][CH:35]1[CH2:40][CH2:39][CH2:38][CH2:37][CH2:36]1)[CH:3]([OH:2])[CH:31]=[CH2:32])=[O:13])([CH3:18])([CH3:17])[CH3:16]Participants
Conditions
- Temperature
- 0 °C
Procedure
To a stirred -78° C. solution of Boc-cyclohexylalanine methyl ester (10.2 g, 35.8 mmol) in dry toluene (60 ml) was added diisobutylaluminum hydride (34 ml of a 1.5M solution in toluene). After 30 min, vinyl magnesium bromide (108 ml of 1M solution in tetrahydrofuran (THF)) was added. After stirring for 15 h at 0° C., the mixture was carefully quenched with methanol, treated with Rochelle salts (22 ml of saturated aqueous solution in 140 ml H2O), and filtered. After extracting the solids 5 times with ethyl acetate, the extracts and filtrate were combined and the organic phase was washed with brine, dried, filtered and evaporated to an oil (10.2 g). Chromatogrphy on silica gel eluting with hexane/ethyl acetate mixtures provided 6.1 g (60%) of the desired product.
Workup
- customthe mixture was carefully quenched with methanol
- additiontreated with Rochelle salts (22 ml of saturated aqueous solution in 140 ml H2O)
- filtrationfiltered
- extractionAfter extracting the solids 5 times with ethyl acetate
- washthe organic phase was washed with brine
- customdried
- filtrationfiltered
- customevaporated to an oil (10.2 g)
Sources & evidence
- ORD record
- ord-28300aa795a1441c8dcd5e1abebded27
- Source dataset
- uspto-grants-1994_09
- Patent number
- US05346887
Reaction notes
Loading…