1,8-Diazabicyclo(5.4.0)undec-7-ene → (Z)-2,2-Dimethyl-5-(tert-butyldimethylsilyloxycarbonyl-methylene)-1,3-dioxolane
Reaction equation
Br[C:2]1([CH2:10][C:11]([O:13][Si:14]([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15])=[O:12])[C:6](=O)[O:5][C:4]([CH3:9])([CH3:8])[O:3]1.N12CCCN=C1CCCCC2>C(Cl)(Cl)(Cl)Cl.O1CCCC1>[CH3:8][C:4]1([CH3:9])[O:5][CH2:6]/[C:2](=[CH:10]/[C:11]([O:13][Si:14]([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:15])[CH3:16])=[O:12])/[O:3]1Participants
5
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
The solution of crude 4-bromo-2,2-dimethyl-5-oxo-1,3-dioxolane-4-acetic acid, tert-butyldimethylsilyl ester (72.4 mmol) in carbon tetrachloride (approximately 220 ml) was cooled to 0–5° C. and treated dropwise over 10 minutes and under vigorous stirring with a solution of 1,8-diazabicyclo[5,4,0]undec-7-ene (12.1 g, 79.6 mmol) in dry tetrahydrofuran (125 ml). A heavy precipitate was formed which gradually became a granular solid. After 1 h, the solid obtained was filtered and washed with a small amount of tetrahydrofuran. The filtrate was concentrated under reduced pressure to give a light orange oil which was used as such for the next step.
Workup
- additiontreated dropwise over 10 minutes
- customA heavy precipitate was formed which
- customthe solid obtained
- filtrationwas filtered
- washwashed with a small amount of tetrahydrofuran
- concentrationThe filtrate was concentrated under reduced pressure
- customto give a light orange oil which
Sources & evidence
- ORD record
- ord-eee7d0ed5fe941f29744c40b28774f19
- Source dataset
- uspto-grants-2006_09
- Patent number
- US07109186B2
Reaction notes
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