CHEM 0310 Study Guide - Final Guide: Malonic Ester Synthesis, Benzoin Condensation, Michael Reaction
Document Summary
Cyclic thioacetals as masked acyl anions to generate alpha-hydroxyketones. Reactions of beta-dicarbonyls: alkylation (malonic ester synthesis; acetoacetic ester synthesis, 1. base; 2. Retro claisen condensation: beta-keto ester without alpha h 2x beginning ester. Occurs via benzyne intermediate when there is no ewg. Occurs via a-e when there is an ewg: via addition-elimination mechanism, ewgs must be in correct positions to stabilize carbanion, nitro groups on meta positions are not stabilizing, via benzyne intermediate ( elimination-addition , halobenzene (1. H+, h2o) phenol: benzyne is an electrophile, 2nd pi bond in benzyne is distorted, and the p orbitals bend out of the ring. Via homogenous pd catalysis: halobenzene + pd pr3, koh phenol, polar solvent like dmf or ch2cl2. Ch2=chchbr: allyl vinyl ether (heat) rearrangement (6 e-, cope rearrangement, non-conjugated diene (heat) rearrangement, oxidation of phenol gives quinone. In order of increasing addition-elimination reactivity (electrophilicity of carbonyl c): amide, ester, carboxylate ion, acyl halide anhydride, acyl halide, carboxylic acid.
