γγ-Disubstituted itaconic acids. Part IV. The Stobbe condensation of 6-benzoyltetralin and 2-benzoylnaphthalene with diethyl succinate

Abstract

The mixture of cis-(I) and trans-(Ph/CO₂Et)-3-ethoxycarbonyl-4-phenyl-4-(6-tetralyl)but-3-enoic acid (VII) has been converted into ethyl 4-acetoxy-5,6,7,8-tetrahydro-1-phenylphenanthrene-2-carboxylate (IIa) and ethyl 4-acetoxy-1-(6-tetralyl)-2-naphthoate (VIIIa). The derived phenolic acids (IIb) and (VIIIb) were converted into methyl 4-methoxy-1-phenylphenanthrene-2-carboxylate (VIc), and 4-methoxy-1-(2-naphthyl)-2-naphthoic acid (XIId), respectively. The latter was decarboxylated to 4-methoxy-1,2′-binaphthyl (XIIe). The anhydrides of cis- and trans-3-carboxy-4-(6-tetralyl)-4-phenylbut-3-enoic acid were isomerised with aluminium chloride to the corresponding indenylacetic acids (V) and (XI), which were cyclised with sodium acetate in acetic anhydride; then hydrolysis and methylation gave the corresponding fluorenones (IIIc) and (IXc), identical with those obtained by cyclisation of the methyl ethers of (IIb) and (VIIIb). Cyclisation of cis(Ph/CO₂Et)-3-ethoxycarbonyl-4-(2-naphthyl)-4-phenylbut-3-enoic acid (XIII; R = Et) by a similar series of reactions gave rise to (VIc).