2-BENZAZEPINES III1, 2 IMPROVED SYNTHESIS OF 2, 3, 4, 5-TETRAHYDRO-2-BENZAZEPIN-1-ONE

3-Methylfuran is an important building block of terpenoid compounds¹⁾ and some of these compounds are biologically active, for example as a defence substance of animal.²⁾ Though many methods have been developed for the syntheses of 3-substituted furan derivatives,³⁾ most of them lack the generality as a synthetic method of (3-furanyl) methyl derivative. Tannis has recently reported the construction of 3-substituted furan derivative by using 3-(lithiomethyl) furan or 3-(chloromagnesium methyl) furan, and demonstrated the generality of his method.⁴⁾