Methanol → methyl (3R)-2-methyl-3-hydroxypentanoate

HRID 2226366Notes

Reaction equation

HRID 2226366 reaction equation
[CH3:1][CH:2]([C@H:7]([O:10]C(=O)CCCCCCCCCCC)[CH2:8][CH3:9])[C:3]([O:5][CH3:6])=[O:4].CO.S(=O)(=O)(O)O>O>[CH3:1][CH:2]([C@H:7]([OH:10])[CH2:8][CH3:9])[C:3]([O:5][CH3:6])=[O:4]

Participants

5

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 54352518HCID 54352518, compound

Product 1

HCID 53772632methyl (3R)-2-methyl-3-hydroxypentanoateYield 38.5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 3.5 g of methyl (3R )-2-methyl-3-dodecanoyloxypentanoate, 12 ml of methanol and 0.5 ml of concentrated sulfuric acid was refluxed for 8 hours, and 20 ml of water was added thereto followed by ether extraction. The ether phase was dried over anhydrous sodium sulfate and ether was distilled away, and then the residue was distilled to give 0.6 g of methyl (3R)-2-methyl-3-hydroxypentanoate of the following formula, b.p. 52.5° C. (2.5 mm Hg), [α]D30 =-10.7° (C=0.61, CHCl3). ##STR97## This compound was converted to (+)-MTPA ester according to a procedure similar to Example 1-(5) and the optical purity determined by 1H-NMR was 95% ee. The NMR chart is shown in FIG. 4.

Workup

  1. temperaturewas refluxed for 8 hours
  2. extractionthereto followed by ether extraction
  3. dry with materialThe ether phase was dried over anhydrous sodium sulfate and ether
  4. distillationwas distilled away
  5. distillationthe residue was distilled

Sources & evidence

ORD record
ord-2a9ed9f18f604455b8dcdd212eef412e
Source dataset
uspto-grants-1994_09
Patent number
US05348870

Reaction notes

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