反应详情

In an analogous manner to that described in the first paragraph of Example 8, from 0.35 g of 6-[5-cyano-2-hydroxy-α-(2-methylpropenyl)benzyl]pyrazine 1-oxide there was obtained 0.02 g of 2-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)pyrazine 1-oxide in the form of a white solid of melting point 166°-168° C. (from diethyl ether).