(2-((3R,5R)-3,5-Bis((tert-butyldimethylsilyl)oxy)cyclohexylidene)ethyl)diphenylphosphine oxide → (R)-1-[(3R,5R)-3,5-bis-(tert-butyldimethyl-silanyloxy)-cyclohexylidene]-7,11-dimethyl-11-trimethylsilanyloxy-dodec-2-ene
Reaction equation
[C:1]([Si:5]([CH3:38])([CH3:37])[O:6][C@H:7]1[CH2:12][C@H:11]([O:13][Si:14]([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15])[CH2:10][C:9](=[CH:21][CH2:22]P(=O)(C2C=CC=CC=2)C2C=CC=CC=2)[CH2:8]1)([CH3:4])([CH3:3])[CH3:2].[Li]CCCC.[CH3:44][C@@H:45]([CH2:51][CH2:52][CH2:53][C:54]([CH3:61])([O:56][Si:57]([CH3:60])([CH3:59])[CH3:58])[CH3:55])[CH2:46][CH2:47][CH2:48][CH:49]=O>C1COCC1>[C:1]([Si:5]([CH3:37])([CH3:38])[O:6][C@H:7]1[CH2:12][C@H:11]([O:13][Si:14]([C:17]([CH3:20])([CH3:18])[CH3:19])([CH3:15])[CH3:16])[CH2:10][C:9](=[CH:21][CH:22]=[CH:49][CH2:48][CH2:47][CH2:46][C@@H:45]([CH3:44])[CH2:51][CH2:52][CH2:53][C:54]([CH3:61])([O:56][Si:57]([CH3:58])([CH3:60])[CH3:59])[CH3:55])[CH2:8]1)([CH3:4])([CH3:2])[CH3:3]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
8.55 g of carefully dried (3R,5R)-[2-[3,5-bis-(t-butyldimethyl-silanyloxy)-cyclohexylidene]-ethyl]-diphenyl-phosphine oxide (Tetrahedron Lett. 32, 7663 (1991)) was dissolved in 90 ml of abs. THF and treated at -78° with 10.9 ml of nBuLi (1.6M, hexane). After 20 minutes, 2.27 g of (S)-5,9-dimethyl-9-trimethylsilanyloxy-decanal, dissolved in a small amount of THF, was added dropwise to the deep red solution. The mixture was kept for 0.5 h at -78° and for 4 h at ambient temperature. After quenching with crushed ice/ KH2PO4, the product was extracted twice with ether, washed with water and brine, dried over sodium sulfate and the solvents removed i.V. Flash chromatography (SiO2, hexane/ AcOEt) yielded in the less polar fractions 3.840 g of (R)-1-[(3R,5R)-3,5-bis-(tert-butyldimethyl-silanyloxy)-cyclohexylidene]-7,11-dimethyl-11-trimethylsilanyloxy-dodec-2-ene, as colorless oil, which was deprotected as described in the following paragraph. 2.40 g of phosphine oxide, which had been used in excess, were recovered in the more polar fractions.
Workup
- additionwas added dropwise to the deep red solution
- waitThe mixture was kept for 0.5 h at -78° and for 4 h at ambient temperature
- customAfter quenching with crushed ice/ KH2PO4
- extractionthe product was extracted twice with ether
- washwashed with water and brine
- dry with materialdried over sodium sulfate
- customthe solvents removed i.V
Sources & evidence
- ORD record
- ord-3da147d7f8d447e1a4c87cd0586f01b2
- Source dataset
- uspto-grants-1999_10
- Patent number
- US05969190
Reaction notes
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