Why is CHS1U1B13S1U1B0ONa not used in the Claisen condensation of ethyl acetate? September 21, 2022 by 8i9x6 CHS1U1B13S1U1B0OS1U1P1-S1S1P0 is a weaker base than the CHS1U1B13S1U1B0CHS1U1B12S1U1B0OS1U1P1-S1S1P0 which is used. CHS1U1B13S1U1B0OS1U1P1-S1S1P0NaS1U1P1+S1S1P0 is more difficult to prepare than CHS1U1B13S1U1B0CHS1U1B12S1U1B0OS1U1P1-S1S1P0NaS1U1P1+S1S1P0. CHS1U1B13S1U1B0OS1U1P1-S1S1P0 would abstract a proton from the ethyl group of the ester. Use of CHS1U1B13S1U1B0OS1U1P1-S1S1P0NaS1U1P1+S1S1P0 would result in transesterification. CHS1U1B13S1U1B0OS1U1P1-S1S1P0NaS1U1P1+S1S1P0 can be used as well as CHS1U1B13S1U1B0CHS1U1B12S1U1B0OS1U1P1-S1S1P0NaS1U1P1+S1S1P0. See Answer Use of CHS1U1B13S1U1B0OS1U1P1-S1S1P0NaS1U1P1+S1S1P0 would result in transesterification.