(+-)-Pantolactone → D-Pantolactone

HRID 1973156Notes

Reaction equation

HRID 1973156 reaction equation
NCC1CC2CC(C2(C)C)C1C.[CH3:13][C:14]1([CH3:21])[C@H:19]([OH:20])[C:17](=[O:18])[O:16][CH2:15]1.CC1(C)C(O)C(=O)OC1>>[CH3:13][C:14]1([CH3:21])[C@@H:19]([OH:20])[C:17](=[O:18])[O:16][CH2:15]1

Participants

4

Reactant 3

HCID 989(+-)-PantolactoneHCID 106576Bicyclo(3.1.1)heptane-3-methanamine, 2,6,6-trimethyl-2×HCID 736053(+)-Pantolactone

Product 1

HCID 439368D-Pantolactone

Procedure

The optically active bases (+)- and (-)-3-aminomethylpinane prove astonishingly stable in the course of the various stages of the process. In none of them are measurable quantities of by-products produced, so that when recycling the (+)- or (-)-3-aminomethylpinane and L-pantolactone for re-use, neither the 3-aminomethylpinane nor the racemized pantolactone has to be subjected to special purification treatments. The optical purity of the D-pantolactone obtained in accordance with the process corresponds, within the limits of analytical error, to the data given in Example 3 for the product obtained from a first separation, even after the optically active base used, the racemized pantolactone left in each case, and the solvent used, have been recycled 20 times; this shows that special purification treatments are not necessary. The new process gives optically pure D-(-)-pantolactone in an overall yield of 90%, based on the DL-pantolactone employed.

Workup

  1. customproduced, so that when
  2. customto be subjected to special purification treatments

Sources & evidence

ORD record
ord-a22f4847e13547e68200158330680eef
Source dataset
uspto-grants-1976_12
Patent number
US03996246

Reaction notes

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