Conversion of 4-oxoproline esters to 4-substituted pyrrole-2-carboxylic acid esters.

The Grignard, Wittig, Tebbe, Horner-Emmons, and Reformatsky reactions of the 4-oxoproline esters gave the corresponding 4-alylated or 4-alkylidenated products, respectively. The products were properly treated with bases to cause aromatization, giving 4-substituted pyrrole-2-carboxylic acid esters such as methyl 4-methylpyrrole-2-carboxylate, which is a trail pheromone of Atta texana.

Stereospecific synthesis of new 4-amino-1,2,3-cyclohexanetricarboxylic acids and 4-amino-1,3-cyclohexanedicarboxylic acids.

Diels-Alder adducts of 1,2-dihydropyridine with maleic and acrylic acid derivatives were stereospecifically converted by way of RuO4 oxidation into new 4-amino-1,2,3-cyclohexanetricarboxylic acids and 4-amino-1,3-cyclohexanedicarboxylic acids.

Stereospecific synthesis of azetidine-cis-2,3-dicarboxylic acid.

Electrocyclic reaction product of 1-(methoxycarbonyl)-1,2-dihydropyridine was stereospecifically converted by RuO(4) oxidation into azetidine-cis-2,3-dicarboxylic acid.