Reactions with Substituents Containing Various Functional Groups

The ( )-5-(l-ferrocenylethyl)thioglycolic acid racts with the optically active ephedrine to give the ( —)-5-(l-ferrocenylythyl)thioglycolic acid, which gives optically active 1-ferrocenylethanol upon treatment with HgCl2/  

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Alkylation of acridine at C-9 occurs on reaction with O)-alkozyalkyl lithium compounds and subsequent oxidation of the resulting 9,10-dihydroacridine derivative (16). Various functional group interconversions are possible leading notably to acridines bearing phosphorus containing substituents at the 9-position (L. Horner and W. Hallenbach, Phosphorus and Sulphur, 1984, 173). 

FIGURE 6.15 Imide formation from a dipeptide sequence containing an aspartyl residue with side-chain functional group in various states followed by generation of two peptide chains resulting from cleavage at the bonds indicated by the dashed arrows. The reaction is catalyzed by base52 or acid. [Merrifield, 1967]. The table shows the effect of the nature of the substituent on the extent of this side reaction. Dmpn = 2,4-dimethylpent-3-yl. 

Disubstituted 3,4-dihydroisoquinolines are easily prepared via cycli-zation of l-(2-aryl-2-isocyanoalkyl)-2-bromobenzenes in the presence of butyl lithium (Scheme 64) (13H389). The precursors to the l-(2-aryl-2-isocyanoalkyl)-2-bromobenzenes were themselves prepared l-bromo-2-(bromomethyl)benzenes and (l-isocyanoalkyl)benzenes in the presence of butyl lithium. The reaction sequence proceeded well with l-bromo-2-(bromomethyl)benzenes containing chlorides (47-58% yields) and methoxy groups (57-58% yields). Additionally, the (l-isocynaoalkyl)benzenes could contain various substituents without a decrease in yields. Trapping of the anion to introduce functionality at C-1 failed. 

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