Several quinonoidal spirolactones (1-oxaspiro[4,5]deca-6,9-diene-2,8-diones) 12 have been synthesized chemically or electrochemically by oxidation of the corresponding tyrosine phenols 3. The spirolactones are of considerable value in peptide chemistry, because they react as active esters with amino acid esters to give dipeptides. In the latter, the side chain of the tyrosine moiety is present as a quinol (4-hydroxycyclohexa-2,5-dien-1-one) system, which can be reduced to the genuine tyrosyl dipeptide. Unsubstituted spirolactones also react as active esters but give dipeptides only in modest yields.
通过相应的
酪氨酸苯酚 3 的氧化作用,用
化学或电
化学方法合成了几种
醌类螺内酯(1-氧杂螺[4,5]癸-6,9-二烯-2,8-二酮)12。
螺内酯在肽
化学中具有相当大的价值,因为它们作为活性酯与
氨基酸酯反应生成二肽。在后者中,
酪氨酸分子的侧链是以醌(
4-羟基环己-2,5-二烯-1-酮)体系的形式存在的,可以还原成真正的
酪氨酸二肽。未取代的
螺内酯也能作为活性酯发生反应,但生成的二肽产量不高。