L-Aspartyl-aminomalonic acid diesters are representatives of new group of sweet compounds. Chemical synthesis of the dipeptide esters was effected by coupling carbobenzoxy-β-benzylaspartic acid with an aminomalonic acid diester by the conventional activated ester method, followed by catalytic hydrogenation to remove the protecting groups. Among the 21 products, trans-2-methyl-cyclohexyl, methyl diester was over 5000 times sweeter than sucrose, 2, 6-dimethyl-cyclohexyl, methyldiester was about 5000 times sweeter and fenchyl, methyl diester was over 20000 times sweeter. These compounds appear to be the most potent sweeteners known of either natural or synthetic origin. On the basis of the potencies of the products, structure-taste relations in the C-terminal part of this molecule were discussed in detail.
