Synthesis and conformational analysis of a dimerising eight-membered lactam dipeptide
作者:Sam Derrer、John E. Davies、Andrew B. Holmes
DOI:10.1039/b003789n
日期:——
The eight-membered lactam dipeptide (3R,8R)-3-acetylamino-8-methoxycarbamoylazocan-2-one was prepared from the L-serine derived (4S)-3-tert-butyloxycarbonyl-4-formyl-2,2-dimethyl-1,3-oxazolidine in 12 steps and 27% overall yield. An extensive conformational analysis both in the solid state and in solution, using NMR, IR and vapour pressure osmometry, was conducted. It was shown that the constrained dipeptide exists in a semi-extended conformation and exhibits a head-to-tail self-recognition (Kdim 100 ± 20 dm3 mol−1 in CDCl2CDCl2). This dimerisation appears to be a general phenomenon in a series of cis-disubstituted medium-ring lactam dipeptides.
通过 12 个步骤,从 L-丝氨酸衍生的 (4S)-3-tert-butyloxycarbonyl-4-formyl-2,2-dimethyl-1,3-oxazolidine 制备出了八元内酰胺二肽 (3R,8R)-3-乙酰氨基-8-甲氧基氨基甲酰偶氮杂环丁烷-2-酮,总收率为 27%。研究人员利用核磁共振、红外光谱和蒸汽压渗透测定法,对该化合物在固态和溶液中进行了广泛的构象分析。结果表明,受约束的二肽以半延伸构象存在,并表现出头对尾的自我识别能力(在 CDCl2CDCl2 中,Kdim 为 100 ± 20 dm3 mol-1)。这种二聚化似乎是一系列顺式二取代中环内酰胺二肽的普遍现象。