Keto-pantoyllactone → D-Pantolactone

HRID 1906589Notes

Reaction equation

HRID 1906589 reaction equation
O=O.[CH3:3][C:4]1([CH3:11])[C:9](=[O:10])[C:7](=[O:8])[O:6][CH2:5]1.FC(F)(F)C([O-])=O.C([N+](CCCC)(CCCC)CCCC)CCC>C1(C)C=CC=CC=1>[CH3:3][C:4]1([CH3:11])[C@@H:9]([OH:10])[C:7](=[O:8])[O:6][CH2:5]1

Participants

5

Reactant 3

HCID 39Keto-pantoyllactoneHCID 977OxygenHCID 3084618N,N,N-Tributylbutan-1-aminium trifluoroacetate

Product 1

HCID 439368D-Pantolactone

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A 500 ml steel autoclave was loaded in a glove box (O2 -content less than 1 ppm) with 40.0 g (0.31 mol) of ketopantolactone, 210 ml of toluene, 180.6 mg (0.389 mmol) of [Rh(COD)2 ]PF6, 254.3 mg (0.389 mmol) of POPPM and 138.3 mg (0.389 mmol) of tetrabutylammonium trifluoroacetate. The hydrogenation was carried out at a constant pressure of 40 bar of H2, at 30° C. and with intensive stirring. By virtue of the exothermic reaction the temperature rose to 58° C. A conversion of above 99% was achieved after 1 hour. After a total hydrogenation time of 2 hours the mixture was worked-up as described in Example 2. Pure (R)-pantolactone was obtained. [α]D20 =-46.6°. Optical purity 90.4%.

Workup

  1. customwas carried out at a constant pressure of 40 bar of H2, at 30° C. and with intensive stirring
  2. customBy virtue of the exothermic reaction the temperature
  3. customrose to 58° C
  4. customAfter a total hydrogenation time of 2 hours

Sources & evidence

ORD record
ord-7b7c738ba1f543f9a17f05b6c521b24b
Source dataset
uspto-grants-1987_03
Patent number
US04652657

Reaction notes

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