Phosphoric Acid → (R)-2-phenyl-1,2-propanediol

HRID 1463735Notes

Reaction equation

HRID 1463735 reaction equation
[OH:1]P(O)(O)=O.[C:6]([O-])([O-])=[O:7].[K+].[K+].CC(C1C=CC=CC=1)=C.C[C:22]1[CH:29]=[CH:28][CH:27]=[CH:26][C:23]=1[CH:24]=[CH2:25]>[Pt].O=[Os](=O)(=O)=O.CC(O)(C)C.O>[C:23]1([C@:24]([OH:1])([CH3:25])[CH2:6][OH:7])[CH:22]=[CH:29][CH:28]=[CH:27][CH:26]=1

Participants

9

Reactant 4

HCID 1004Phosphoric AcidHCID 7407Alpha-MethylstyreneHCID 11430Potassium CarbonateHCID 119042-Methylstyrene

Product 1

HCID 6951538(R)-2-phenyl-1,2-propanediolYield 95%

Reagents, catalysts & solvents 4

HCID 23939PlatinumCatalystHCID 30318Osmium TetroxideCatalystHCID 962WaterSolventHCID 6386tert-ButanolSolvent

Procedure

A flow cell reactor filled with a 100 cm2 platinum on titanium anode and a 100 cm2 stainless steel cathode--the two electrode compartment being divided by a Nafion® cation exchange membrane--is used. A solution of 5% H3PO4 is circulated through the cathode compartment, while a solution of anolyte consisting of the followings: H2O (2 liters), t-BuOH (2 liters), K3Fe(CN)6 (0.24 mole, 91 g), K2CO3 (4.8 mole, 662 g), the chiral ligand, PHAL-DHQD (0.012 mole, 9.3 g), OsO4 (0.2 M in toluene, 0.0008 mole, 4 mL) and α-methylstyrene (1.6 mole, 189 g) is circulated through the anode compartment. A constant current of 3 A (current density 30 mA/cm2) is applied at 15° C. until almost all the o-methylstyrene is consumed (the reaction is followed by thin layer chromatography on silica gel). The product is isolated as described above (Example 6.1) to provide (R)-2-phenyl-1.2-propanediol in 95% yield and 90% ee.

Workup

  1. customis applied at 15° C.
  2. customis consumed (the reaction
  3. customThe product is isolated

Sources & evidence

ORD record
ord-8920a12f17ad4058a7083a7296b522a1
Source dataset
uspto-grants-1994_04
Patent number
US05302257

Reaction notes

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