Ethylene glycol acetal

Ethylene glycol acetal scheme

Protection :

  • Reagents
    Solvents
    Temperature
    Time
    Yield
  • (CH2OH)2 TsOH
    PhMe
    Reflux
    4 h
    93 %
    intermediate structure
    TsOH, (CH2OH)2
    PhMe
    Reflux, 4 h, 93%
    intermediate structure
  • (TMSOCH2)2 TMSOTf
    CH2Cl2
    -78 - -15 °C
    90 min
    99 %
    intermediate structure
    (TMSOCH2)2, TMSOTf
    CH2Cl2
    -78 to -15 °C, 90 min, 99%
    intermediate structure
  • (CH2OH)2 Dowex 50WX8
    PhH
    Reflux
    30 h
    90 %
    intermediate structure
    (CH2OH)2, Dowex 50WX8
    PhH
    Reflux, 30 h, 90%
    intermediate structure
  • (CH2OH)2 TsOH
    PhH
    Reflux
    6 h
    95 %
    intermediate structure
    (CH2OH)2, TsOH
    PhH
    Reflux, 6 h, 95%
    intermediate structure

Deprotection :

  • Reagents
    Solvents
    Temperature
    Time
    Yield
  • HCl
    EtOH H2O
    RT
    4 h
    100 %
    intermediate structure
    HCl
    EtOH, H2O
    RT, 4 h, 100%
    intermediate structure
  • TsOH
    Acetone H2O
    Reflux
    15 min - 2.5 h
    84-97 %
    intermediate structure
    TsOH
    Acetone, H2O
    Reflux, 2.5 h, 84%
    intermediate structure
    intermediate structure
    TsOH
    Acetone, H2O
    Reflux, 15 min, 97%
    intermediate structure
  • Pyr.TsOH
    Acetone H2O
    RT
    24 h
    98 %
    intermediate structure
    Pyr.TsOH
    Acetone, H2O
    RT, 24 h, 98%
    intermediate structure
  • Ph3C+ BF4-
    CH2Cl2
    RT
    2 h
    92 %
    intermediate structure
    Ph3C+ BF4-
    CH2Cl2
    RT, 2 h, 92%
    intermediate structure
  • Camphorsulfonic acid
    Acetone
    RT
    2 d
    62 %
    intermediate structure
    Camphorsulfonic acid
    Acetone
    RT, 2 d, 62%
    "The yield was 90 % brsm."
    intermediate structure
  • H2SO4
    N/A
    RT
    30.5 h
    92 %
    intermediate structure
    H2SO4
    RT, 30.5 h, 92%
    intermediate structure
  • TsOH
    THF MeOH H2O
    RT
    60 min
    90 %
    intermediate structure
    TsOH
    THF, MeOH, H2O
    RT, 60 min, 90%
    intermediate structure