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Bumped by Community user
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Mithoron
Mithoron
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TexbooksTextbooks say removing proton from thiaminethiamine's C atom will produce a resonance stabilized carbanion which is hence bioactive. Thats ok. ButThat's OK, but how comes that 1) we abstract the acidic proton with the OH base whose pK is lower that for thiamine, and 2) the remaining anion acts - in bio context - in aqua medium (?), hence will immediately deprotonate water and lose its negative charge.

deprotonation of thiamine's thiazolium ring

Texbooks say removing proton from thiamine C atom will produce a resonance stabilized carbanion which is hence bioactive. Thats ok. But how comes that 1) we abstract the acidic proton with the OH base whose pK is lower that for thiamine, and 2) the remaining anion acts - in bio context - in aqua medium (?), hence will immediately deprotonate water and lose its negative charge.

Textbooks say removing proton from thiamine's C atom will produce a resonance stabilized carbanion which is hence bioactive. That's OK, but how comes that 1) we abstract the acidic proton with the OH base whose pK is lower that for thiamine, and 2) the remaining anion acts - in bio context - in aqua medium (?), hence will immediately deprotonate water and lose its negative charge.

deprotonation of thiamine's thiazolium ring

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Evgeny
Evgeny
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Acidity of thiamine - how comes hydroxide anion with pK about 15 ionizes thiamine with pK about 18?

Texbooks say removing proton from thiamine C atom will produce a resonance stabilized carbanion which is hence bioactive. Thats ok. But how comes that 1) we abstract the acidic proton with the OH base whose pK is lower that for thiamine, and 2) the remaining anion acts - in bio context - in aqua medium (?), hence will immediately deprotonate water and lose its negative charge.