SYNTHESIS OF AN INTERMEDIATE, 7,8-DIMETHYL-2-TETRALONE, FOR OCCIDOL ISOMER-I AND OCCIDOL ISOMER-II

Anisole is succinoylated with succinic anhydride to yield 3-(p-methoxy benzoyl) propionic acid 3. The acid on Clemmensen reduction gives 4-(p -methoxy phenyl) butyric acid 4 which on esterification affords methyl 4-(p-methoxyphenyl)butyrate 5. The ester 5 on reaction with methylmag nesium iodide gives 5-(p-methoxyphenyl)-2-methylpentan-2-ol 6 which is cyclised with PPA to furnish 7-methoxy-1,1-dimethyltetralin 7. The te tralin 7 undergoes aromatization with p-chloranil or DDQ to afford 7-m ethoxy1,2-dimethyl naphthalene 8, the reduction of which with sodium i n liquid ammonia as well as with sodium in ethanol yields 7,8-dimethyl -2-tetralone 10.