1,1,1-Trimethoxy-2-methylpropane → HCID 10351919, compound

HRID 1769045Notes

Reaction equation

HRID 1769045 reaction equation
CO[C:3](OC)(OC)[CH:4]([CH3:6])[CH3:5].[OH:11][C@@H:12]([CH2:14][C@H:15]([OH:17])[CH3:16])[CH3:13]>C1(C)C=CC=CC=1.CC1C=CC(S([O-])(=O)=O)=CC=1.C1C=C[NH+]=CC=1>[C:4](=[C:3]1[O:17][C@H:15]([CH3:16])[CH2:14][C@@H:12]([CH3:13])[O:11]1)([CH3:6])[CH3:5]

Participants

5

Reactant 2

HCID 404951,1,1-Trimethoxy-2-methylpropaneHCID 27236832,4-Pentanediol, (-)-

Product 1

HCID 10351919HCID 10351919, compoundYield 52.5%

Reagents, catalysts & solvents 2

HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)CatalystHCID 1140TolueneSolvent

Procedure

To a mixture of 3.8 g (25.6 mmol) of 1,1,1-trimethoxyisobutane and 3 g (28.8 mmol) of 2(R),4(R)-dihydroxypentane in 100 ml of toluene was added 200 mg of PPTS and the resulting reaction mixture was allowed to reflux under nitrogen for 20 hours while azeotroping methanol formed using the Dean-Stark trap. The reaction mixture was cooled, washed successively with saturated sodium bicarbonate solution, water, and brine. The toluene layer was dried, the solvent was concentrated under nitrogen, and the residue was distilled to afford 2.1 g (52.5%) of 2-isopropylidene-4(R),6(R)-dimethyl-1,3-dioxane (Formula V: R3 =R4 =CH3 ; R5 and R6 together are (R,R)--O--CH(CH3)CH2CH(CH3)O--), b.p. 95°-100° C./10 mm.

Workup

  1. customthe resulting reaction mixture
  2. temperatureto reflux under nitrogen for 20 hours
  3. customwhile azeotroping methanol
  4. customformed
  5. temperatureThe reaction mixture was cooled
  6. washwashed successively with saturated sodium bicarbonate solution, water, and brine
  7. dry with materialThe toluene layer was dried
  8. concentrationthe solvent was concentrated under nitrogen
  9. distillationthe residue was distilled

Sources & evidence

ORD record
ord-4260bebcb65645498e899359d0ca0da3
Source dataset
uspto-grants-1995_01
Patent number
US05380729

Reaction notes

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