Trisubstituted aromatic compound synthesis

Oxidation of Aromatic Compounds Reduction of Aromatic Compounds Synthesis of Trisubstituted Benzenes... 

The co-operative effect of 1,3-interrelated directing groups is a powerful strategy in synthesis. This allows the otherwise difficult preparation of 1,2,3-trisubstituted aromatic compounds. Hence the lithiation of the aromatic compound 129 is directed by both the methoxy and secondary amide groups (1.118). Two equivalents of the... 

We see what interest is attached to the study of active aromatic compounds, and how necessary it is that chemists who are dealing with bi- and trisubstitution products of benzene capable of being active should attempt the separation of their dextro- and laevorota-tory isomers. We shall proceed to show that bodies obtained by synthesis consist, in fact, of equal proportions of these isomers. 

In the laboratory of P. Kocovsky, novel pyridine-type P,A/-ligands were prepared from various monoterpenes. The key step was the Krohnke pyridine synthesis, and the chirality was introduced by the a,(3-unsaturated ketone component, which was derived from enantiopure monoterpenes. One of these ligands was synthesized from (+)-pinocarvone which was condensed with the acylmethylpyridinium salt under standard conditions to give good yield of the trisubstituted pyridine product. The benzylic position of this compound was deprotonated with butyllithium, and upon addition of methyl iodide the stereoselective methylation was achieved. The subsequent nucleophilic aromatic substitution (Sw/ r) gave rise to the desired ligand. 

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