Synthesis of a fragment a derivative of an antibiotic, nosiheptide
Two 4-ethoxycarbonyl thiazoyly groups were introduced into 2- and 5- positions of 3-hydroxypyridine in 8 steps using 5-cyano-3-hydroxypyridine (2) as the starting material. The pyridine derivative obtained in the last step was converted to a fragment. A derivative (21) by stepwise introduction of the 2-substituted 4-thiazolyl group into the 6-position. The total yield for the formation of 21 via 14 steps was 7.6%.