The conversion of 4oxocyclohexanecarboxaldehyde dimethyl acetal (VIII) to 2-acetamid0-5, 6, 7, 8-tetrahydro-Phydroxy-6-quinazolinecarboxaldehyde (XIV) provided the key intermediate for an improved synthesis of 5, 8-dideaza-5, 6, 7, 8-tetrahydrofolic acid (I). The transformation of XIV to I wm accomplished either by the direct reductive alkyla, tion of p aminobenzoyl-cglutamic acid with XIV, followed by hydrolysis, or by the preparation of p [( ...
