CHEM F311 Lecture 35 Dielsssss Alder.pptx

Notes

1. CHEM F311 Organic Chemistry – III Lecture 35 – 07 th Nov. 2024

2. Preview Use of acetylenes Diels – Alder reaction Stereospecific Stereoselective Regioselective Recap Synthesis of carbonyl compounds – carbonyl condensation 1,3-Dicarbonyl compounds β – hydroxyl carbonyl compounds Synthesis of α , β – unsaturated carbonyl compounds

3. Carbonyl condensation All the compounds have 1,3 relationship and can be made from alcohol, ketone(or aldehyde) and carboxylic acid derivatives Synthesis of difunctionalised compounds with odd numbered relationships need only synthons of natural polarity; while opposite is true for difunctionalised compounds with even numbered relationships.

4. Understanding 1,3-relationship Two-group disconnections: 1,3-difunctional compounds & α , β -unsaturated carbonyl compounds 1,3-Dicarbonyl compounds Route (a) is preferred as it is self condensation of the molecule (ethyl acetate)

5. β - hydroxy carbonyl compounds