4-Bromo-2,2-dimethyl-5-oxo-1,3-dioxolane-4-acetic acid, tert-butyldimethylsilyl ester → (Z)-2,2-dimethyl-5-(tert-butyldimethylsilyloxycarbonylmethylene)-1,3-dioxolan-4-one

HRID 392818Notes

Reaction equation

HRID 392818 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:7])[O:5][C:4]([CH3:9])([CH3:8])[O:3]1>C(Cl)(Cl)(Cl)Cl.O1CCCC1>[CH3:8][C:4]1([CH3:9])[O:5][C:6](=[O:7])/[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]1

Participants

4

Reactant 1

HCID 235191444-Bromo-2,2-dimethyl-5-oxo-1,3-dioxolane-4-acetic acid, tert-butyldimethylsilyl ester

Product 1

HCID 60104830(Z)-2,2-dimethyl-5-(tert-butyldimethylsilyloxycarbonylmethylene)-1,3-dioxolan-4-one

Reagents, catalysts & solvents 2

HCID 5943Carbon TetrachlorideSolventHCID 8028TetrahydrofuranSolvent

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 (˜220 ml) was cooled to 0-5° C. and treated dropwise over 10 min. and under good stirring with a solution of 1,8-diazabcyclo 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

  1. additiontreated dropwise over 10 min.
  2. customA heavy precipitate was formed which
  3. customthe solid obtained
  4. filtrationwas filtered
  5. washwashed with a small amount of tetrahydrofuran
  6. concentrationThe filtrate was concentrated under reduced pressure
  7. customto give a light orange oil which

Sources & evidence

ORD record
ord-562d87a7f7414fbf9b126877ecb3be7e
Source dataset
uspto-grants-2004_10
Patent number
US06803378B2

Reaction notes

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