A convenient method is presented for the asymmetric synthesis of axially chiral 1,1′:5′,1″- and 1,1′:4′,1″- ternaphthalenes via the ester-mediated nucleophilic aromatic substitution reaction. Thus, treatment of dimenthyl 1,5-dimenthoxynaphthalene-2,6- dicarboxylate 7 and its regioisomer, dimenthyl 1,4-dimenthoxynaphthalene-2,3- dicarboxylate 10, with 2-methoxynaphthalen-1-ylmagnesium bromide 12 gave enantiomerically and diastereomerically pure dimenthyl 2,2″-dimethoxy-1, 1′:5′,1″-ternaphthalene-2′,6′-dicarboxylate 3 and dimenthyl 2,2″-dimethoxy-1,1′:4′,1″-ternaphthalene- 2′,3′-dicarboxylate 4 in 70% and 63% yields, respectively, after chromatographic purification.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry