User:Benjah-bmm27/degree/2/PJW

Introduction

"Difunctional Carbonyl Compounds", Dr Paul Wyatt.

Common dicarbonyls

• Diketone
• Malonates, e.g. dimethyl malonate, diethyl malonate
• Other 1,3-dicarbonyls, e.g. ethyl acetoacetate

Reactions and synthesis of dicarbonyls

• Claisen condensation makes 1,3-dicarbonyls
• Keto-enol tautomerism in dimedone 95% enol (c.f. cyclohexanone 0.004% enol and ethyl acetoacetate 7.5% enol)
• Acetoacetic ester synthesis
• Knoevenagel condensation
• Decarboxylation: NaOH then H⁺, heat (via cyclic 6-membered transition state)
• Krapcho decarboxylation (LiI, wet DMSO)
• Control groups
• Double deprotonation of 1,3's with KNH₂
• Enones: conjugate (1,4) addition (e.g. Michael reaction) vs. direct (1,2) addition
• Hard and soft nucleophiles and electrophiles
• Michael reaction, nucleophilic conjugate addition, Gilman reagents
• Dithianes (hard nucleophile at carbonyl carbon)
• Nef reaction
• McMurry reaction
• Darzens reaction
• Benzoin condensation
• Acyloin condensation
• Pinacol coupling reaction
• Robinson annulation: ChemTube3D animation
• OsO₄: Upjohn dihydroxylation

Might have been mentioned

• Dieckmann condensation