1,8-Diazabicyclo(5.4.0)undec-7-ene → (Z)-2,2-Dimethyl-5-(tert-butyldimethylsilyloxycarbonyl-methylene)-1,3-dioxolane

HRID 1836456Notes

Reaction equation

HRID 1836456 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]1

Participants

5

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 minutes and under good 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

  1. additiontreated dropwise over 10 minutes
  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-1d2bb2242cfd4bcc80a8ab0f8137cf27
Source dataset
uspto-grants-2004_08
Patent number
US06777440B2

Reaction notes

Loading…