Benzaldehyde → HCID 11346195, compound

HRID 992665Notes

Reaction equation

HRID 992665 reaction equation
[CH:1](=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[O:9]=[CH:10][C@@H:11]([C@H:13]([C@H:15]([C@@H:17]([CH2:19][OH:20])[OH:18])O)[OH:14])[OH:12]>[Cl-].[Cl-].[Zn+2]>[CH2:19]1[O:20][CH:1]([C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)[O:8][C@H:15]([C@H:13]([OH:14])[C@@H:11]([OH:12])[CH:10]=[O:9])[C@@H:17]1[OH:18]

Participants

4

Reactant 2

HCID 240Benzaldehyde2×HCID 3037556(2R,3S,4S,5R)-2,3,4,5,6-pentahydroxyhexanal

Product 1

HCID 11346195HCID 11346195, compound

Reagents, catalysts & solvents 1

HCID 3007855ZincchlorideCatalyst2×

Procedure

A portion of ZnCl2 (23 kg, 171 mol) was placed into a reactor, taking measures to exclude moisture. Benzaldehyde (70 L, 680 mol) was poured into the reactor, and the mixture was stirred for about 30 minutes using a powerful mechanical stirrer. After initial dissolution of zinc chloride, a thick slurry of a benzaldehyde-ZnCl2 complex forms. Anhydrous D-galactose (30 kg, 164 mol) and more benzaldehyde (60 L, 570 mol) were added to the warm slurry, and the mixture was allowed to react at RT for 24 hours with vigorous stirring. The precipitate was filtered off and washed portionwise with benzaldehyde (10-15 L total) and then with acetone, to give, after air-drying, 6-7 kg of unreacted D-galactose, probably as the monohydrate. The combined filtrate and benzaldehyde washings were diluted with ether (70 L) and petroleum ether (80 L), and the mixture was extracted with ice-cold water (140 L) . The organic layer was washed 3 times with ice water (70 L each time), and the combined aqueous layers were neutralized by rapid addition of a solution of potassium carbonate (38 kg of anhydrous carbonate in approximately 45-50 L of water). The resulting thick suspension of zinc salts was filtered, and the precipitate was washed thoroughly with water until 500-600 L of filtrate were collected. After extraction with chloroform (70 L) and with petroleum ether (70 L), the filtrate, containing 4,6-O-benzylidene-D-galactose (2) and a mixture of KCl and KHCO3, and having a pH of about 8.7, was used directly for the following oxidation.

Workup

  1. customto react at RT for 24 hours with vigorous stirring
  2. filtrationThe precipitate was filtered off
  3. washwashed portionwise with benzaldehyde (10-15 L total)
  4. customwith acetone, to give
  5. customafter air-drying
  6. additionThe combined filtrate and benzaldehyde washings were diluted with ether (70 L) and petroleum ether (80 L)
  7. extractionthe mixture was extracted with ice-cold water (140 L)
  8. washThe organic layer was washed 3 times with ice water (70 L each time)
  9. additionthe combined aqueous layers were neutralized by rapid addition of a solution of potassium carbonate (38 kg of anhydrous carbonate in approximately 45-50 L of water)
  10. additionThe resulting thick suspension of zinc salts
  11. filtrationwas filtered
  12. washthe precipitate was washed thoroughly with water until 500-600 L of filtrate
  13. customwere collected
  14. extractionAfter extraction with chloroform (70 L)
  15. additionwith petroleum ether (70 L), the filtrate, containing 4,6-O-benzylidene-D-galactose (2)
  16. additiona mixture of KCl and KHCO3

Sources & evidence

ORD record
ord-537949b59af640ee9ce55c20fa6f28ae
Source dataset
uspto-grants-2002_10
Patent number
US06469148B1

Reaction notes

Loading…