Preparation of Functionalized, Conformationally Constrained DTPA Analogues from <scp>l</scp>- or <scp>d</scp>-Serine and <i>trans</i>-4-Hydroxy-<scp>l</scp>-proline. Hydroxymethyl Substituents on the Central Acetic Acid and on the Backbone
作者:I. Fraser Pickersgill、Henry Rapoport
DOI:10.1021/jo000071g
日期:2000.6.1
acetic acid or on the backbone are described. Key synthetic steps include (i) displacement of the 4-hydroxyl group of N-BOC-trans-4-hydroxy-L-proline benzyl ester, via activation as the triflate, with suitable amines derived from L- or D-serine, (ii) the low-temperature alkylation of diethylenetriamines with the triflate of benzyl glycolate, thereby minimizing competitive lactamization, to give DTPA pentabenzyl
描述了构象受限的二亚乙基三胺五乙酸(DTPA)类似物的对映体和非对映体特异性合成物,它们在中央乙酸或主链上被羟甲基连接基取代基官能化。关键的合成步骤包括(i)用三氟甲磺酸酯活化,用衍生自L-或D-丝氨酸的合适胺置换N-BOC-反式-4-羟基-L-脯氨酸苄酯的4-羟基基团,( ii)用乙二醇酸苄酯的三氟甲磺酸酯对二亚乙基三胺进行低温烷基化,从而将竞争性内酰胺化减至最少,从而得到DTPA五苄基酯,以及(iii)在非常温和的氢解条件下脱保护得到相应的DTPA类似物。