Acetic Acid → (E)-3-formylbut-2-enyl acetate

HRID 894851Notes

Reaction equation

HRID 894851 reaction equation
C([O:4][CH:5](OC(=O)C)[C:6]([CH3:13])=[CH:7][CH2:8][O:9][C:10](=[O:12])[CH3:11])(=O)C.C(O)(=O)C>O>[C:10]([O:9][CH2:8]/[CH:7]=[C:6](\[CH3:13])/[CH:5]=[O:4])(=[O:12])[CH3:11]

Participants

4

Reactant 2

HCID 176Acetic AcidHCID 538659791,1,4-Triacetoxy-2-methyl-2-butene

Product 1

HCID 6365337(E)-3-formylbut-2-enyl acetateYield 81.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

48.8 parts of 1,1,4-triacetoxy-2-methyl-but-2-ene, consisting, according to NMR analysis, of 46.4% of (E)-isomer and 53.6% of (Z)-isomer, are boiled with 500 parts of glacial acetic acid and 18 parts of water for 2.5 hours. After stripping off the acid and water on a rotary evaporator at from 40° to 50° C. under a waterpump vacuum, fractional distillation of the residue gives 23.2 parts of 4-acetoxy-2-methylcrotonaldehyde (81.6% of theory) of boiling point 102°-103° C./23.9 mbar (nD20 =1.4641). According to NMR analysis (aldehyde protons), the aldehyde obtained consists of 98.0% (E)- and 2.0% (Z)-4-acetoxy-2-methylcrotonaldehyde.

Workup

  1. customon a rotary evaporator at from 40° to 50° C.
  2. distillationunder a waterpump vacuum, fractional distillation of the residue

Sources & evidence

ORD record
ord-5d1715a672004d17966150e2ef3982da
Source dataset
uspto-grants-1981_08
Patent number
US04284796

Reaction notes

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