Friedel-Craft’s acylation

Treatment of [3] with acetylchloride in dichloroethane m the presence of AICI3 (Friedel-Craft s acylation) gives tetrahydrotetramethylacetylnaphthalene [4], which can be converted to tetrahydrotetramethylnaphthoic acid [5] by treatment with high-test bleaching powder (haloform reaction) (4,6). 

Although the above route differs slightly from the synthesis of the related chiral biphenyls [i.e. (5 )-(+)-4-(3-methylpentyl)-4 -cyanobiphenyl (41, n = 1 and /w = 1)], the other chiral methyl substituted alkanoic acids (37) are obtained by various transformations from (5)-(+)-2-methylbutyl bromide (18) the acyl groups are introduced into the aromatic core by conversion of the acids to their acid chlorides (38) followed by Friedel-Craft s acylation and subsequent Huang-Minion reduction of the chiral methyl substituted alkanoylbromobiphe-nyls (40). This general approach is demonstrated in Scheme 5. 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ , ]

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