Cov ketones puas tuaj yeem ua rau aldol condensation?
Cov ketones puas tuaj yeem ua rau aldol condensation?

Video: Cov ketones puas tuaj yeem ua rau aldol condensation?

Video: Cov ketones puas tuaj yeem ua rau aldol condensation?
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Txawm tias ketone lub cev enolates yog zoo nucleophiles, cov aldol cov tshuaj tiv thaiv ntawm ketones feem ntau tsis yog tshwj xeeb yog kev vam meej. Cov no Aldol cov khoom ua tau feem ntau nyob rau hauv lub cev qhuav dej (poob dej) los muab cov kab ke sib txuas (kev tshem tawm tshuaj tiv thaiv ) (tag nrho = ib aldol condensation ntawm daim tawv nqaij ).

Ib yam li ntawd, hom aldehydes thiab ketones tau txais aldol condensation li cas?

Aldehydes thiab ketones muaj tsawg kawg yog ib qho α-hydrogen undergo aldol condensation . Cov tebchaw (ii) 2-methylpentanal, (v) cyclohexanone, (vi) 1-phenylpropanone, thiab (vii) phenylacetaldehyde muaj ib lossis ntau dua α-hydrogen atoms. Yog li ntawd, cov no undergo aldol condensation.

Ib tug kuj yuav nug, dab tsi yog cov qauv kev cai rau aldol condensation? Cov aldol cov tshuaj tiv thaiv xav tau ib qho aldehyde los yog ketone uas muaj tsawg kawg ib a-hydrogen. Cov a-carbon ua nucleophilic thaum nws yog deprotonated los ntawm lub hauv paus. Cov carbonyl carbon yog electrophilic. Coulomb Txoj Cai coj ob hom kev them nyiaj sib txawv no ua ke los tsim C-C daim ntawv cog lus.

Tsis tas li ntawd, puas yog ketone muab aldol condensation?

Aldol ua kua : Ib qho ntxiv tshuaj tiv thaiv ntawm ob aldehydes, ob ketones , los yog aldehyde thiab a ketone lub cev , ua rau muaj β-hydroxy aldehyde los yog β-hydroxy ketone lub cev . Tom qab lub cev qhuav dej ua rau α, β-unsaturated aldehyde lossis ketone lub cev . Cov kauj ruam ntxiv yam tsis muaj lub cev qhuav dej tom qab yog ib aldol cov tshuaj tiv thaiv.

Can aldol condensation tshwm sim hauv acidic nruab nrab?

Aldol ua kua tshuaj tiv thaiv ua tau ua ob kua qaub catalyzed los yog puag catalyzed. Nplooj ntawv no hais txog cov kua qaub catalytic mechanism ntawm cov khoom aldol ua tshuaj tiv thaiv. Qhov no condensation Nws feem ntau ua raws li lub cev qhuav dej vim β-tawm los tsim ib qho α, β-unsaturated aldehyde lossis α, β-unsaturated ketone.

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