Ethylene glycol acetal

Protection :
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ReagentsTimeYield
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(CH2OH)2 TsOH4 h93 %(CH2OH)2, TsOHPhMeReflux, 4 h, 93%
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TMSOTf (TMSOCH2)290 min99 %TMSOTf, (TMSOCH2)2CH2Cl2-78 to -15 °C, 90 min, 99%
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(CH2OH)2 Dowex 50WX830 h90 %(CH2OH)2, Dowex 50WX8PhHReflux, 30 h, 90%
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(CH2OH)2 TsOH6 h95 %(CH2OH)2, TsOHPhHReflux, 6 h, 95%
Deprotection :
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ReagentsTimeYield
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HCl4 h100 %HClEtOH, H2ORT, 4 h, 100%
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TsOH15 min - 2.5 h84-97 %
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Pyr.TsOH24 h98 %Pyr.TsOHAcetone, H2ORT, 24 h, 98%
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Ph3C+ BF4-2 h92 %Ph3C+ BF4-CH2Cl2RT, 2 h, 92%
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Camphorsulfonic acid2 d62 %Camphorsulfonic acidAcetoneRT, 2 d, 62%"The yield was 90 % brsm."
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H2SO430.5 h92 %H2SO4RT, 30.5 h, 92%
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TsOH60 min90 %TsOHH2O, MeOH, THFRT, 60 min, 90%