A Novel Synthesis of Isoquinoline Derivatives

Abstract

Reaction of 4-cyano-1-methyl-2(1B)-pyridone (Ia) wlth 2,3-dimethyl-1,3-hutadiene (11) at 170' gave &-4a-cyano-4 a , 5 , 8 , 8 a -t e t r a h y d r 0 -2 , 6 , 7 -t r i m e t h y l -1 ( 2 ) -i u i n n (IIIa) in a good yleld and at 190' gave IIIa, --4a-cyano-4a,5,8,8atetrahydro-2,6,7-trimethyl-1(2H)-isoqulnln (IVa), and 2,6,7trimethyl-l(2H)-isaquinolone (V).Heating of 4-methoxycarbonyl-1-methyl-2(lB)-pyridone (Ib) with I1 gave 9-4a,5,8,8a-tetrahydro-4a-methoxycarbonyl-2,6,7-trimethyl-l(2)-isunolone