Acetic Acid → (2S,3R,4S)-2-methyl-3,4-dihydro-2H-pyran-3,4-diol

HRID 1154884Notes

Reaction equation

HRID 1154884 reaction equation
[CH3:1][C@@H:2]1[O:7][CH:6]=[CH:5][C@H:4]([O:8]C(C)=O)[C@H:3]1[O:12]C(C)=O.C[O-].[Na+].C(O)(=O)C>CO>[CH3:1][C@@H:2]1[O:7][CH:6]=[CH:5][C@H:4]([OH:8])[C@H:3]1[OH:12]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 2734733L-arabino-Hex-1-enitol, 1,5-anhydro-2,6-dideoxy-, diacetateHCID 10942334Sodium Methoxide

Product 1

HCID 10986248(2S,3R,4S)-2-methyl-3,4-dihydro-2H-pyran-3,4-diol

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

10 grams of 3,4-di-O-acetyl-L-rhamnal is dissolved in 100 milliliters of methanol, and the pH is adjusted to 8 to 9 by the dropwise addition of a freshly prepared solution of sodium methoxide in methanol. The flask is sealed and allowed to stand at 0°-5° C. overnight after which time deacetylation is complete. The solution is neutralized by the careful dropwise addition of glacial acetic acid, and then the solvent is removed under reduced pressure. The resulting clear syrup is co-evaporated several times with toluene to remove any excess acetic acid, and the syrup crystallizes during these evaporations to give L-rhamnal. The yield of this compound is 6 grams.

Workup

  1. customThe flask is sealed
  2. customthe solvent is removed under reduced pressure
  3. customto remove any excess acetic acid
  4. customthe syrup crystallizes during these evaporations

Sources & evidence

ORD record
ord-66bde99a6948477a94500858fced76a5
Source dataset
uspto-grants-1981_11
Patent number
US04298726

Reaction notes

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