2,2-Dimethoxypropane → 2-[(4R, 6S)-2,2-dimethyl-6-benzoyloxymethyl-1,3-dioxan-4-yl]acetic tert-butyl ester

HRID 10132

Reaction equation

HRID 10132 reaction equation
[C:1]([O:5][C:6](=[O:23])[CH2:7][CH:8]([OH:22])[CH2:9][C@H:10]([OH:21])[CH2:11][O:12][C:13](=[O:20])[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)([CH3:4])([CH3:3])[CH3:2].CO[C:26](OC)([CH3:28])[CH3:27].C(=O)([O-])O.[Na+]>C(Cl)Cl>[C:1]([O:5][C:6](=[O:23])[CH2:7][C@H:8]1[CH2:9][C@@H:10]([CH2:11][O:12][C:13](=[O:20])[C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=2)[O:21][C:26]([CH3:28])([CH3:27])[O:22]1)([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 3

HCID 64952,2-DimethoxypropaneHCID 516892Sodium BicarbonateHCID 21040752(5S)-6-benzoyloxy-3,5-dihydroxyhexanoic tert-butyl ester

Product 1

HCID 101333842-[(4R, 6S)-2,2-dimethyl-6-benzoyloxymethyl-1,3-dioxan-4-yl]acetic tert-butyl esterYield 72%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
20 °C

Procedure

To a solution composed of 8.94 g (27.6 mmol) of (5S)-6-benzoyloxy-3,5-dihydroxyhexanoic tert-butyl ester produced in Example 15, 35.8 mL of 2,2-dimethoxypropane, and 2.5 mL of methylene chloride was added 269 mg (1.4 mmol) of p-toluenesulfonic acid-1H2O, and the mixture was stirred at 20° C. for 4 hours, after which 500 mL of saturated sodium hydrogen carbonate solution was added. The aqueous layer was separated and further extracted with 2 portions of methylene chloride, 20 mL each, and the organic layers were combined. The combined solution was dehydrated over anhydrous sodium sulfate and the solvent was distilled off under reduced pressure to give a colorless oil. This residue was purified by silica gel column chromatography (Kieselgel 60, product of Merck; hexane:acetone=10:1) to give 7.24 g of 2-[(4R,6S)-2,2-dimethyl-6-benzoyloxymethyl-1,3-dioxan-4-yl]acetic tert-butyl ester (white solid). Yield: 72%.

Workup

  1. customThe aqueous layer was separated
  2. extractionfurther extracted with 2 portions of methylene chloride, 20 mL each
  3. distillationthe solvent was distilled off under reduced pressure
  4. customto give a colorless oil
  5. customThis residue was purified by silica gel column chromatography (Kieselgel 60, product of Merck; hexane:acetone=10:1)

Sources & evidence

ORD record
ord-980177fca8a041c8ab1d3755eefdece6
Source dataset
uspto-grants-2006_08
Patent number
US07094594B2

Linked notes

Loading…