Synthesis of a New Dual Metalloprotease Inhibitor. II. Stereoselective Synthesis of Peptidomimetic [5.7]-Bicyclic Compounds.
作者:Kozo AKASAKA、Yuki KOMATSU、Katsuya TAGAMI、Toshikazu SHIMIZU、Naoyuki SHIMOMURA、Hiroshi NAKA、Kenji HAYASHI、Shigeto NEGI
DOI:10.1248/cpb.47.1532
日期:——
An efficient synthetic process for the key intermediate of a new peptidomimetic dual metalloprotease inhibitor, ER-40133, was developed. (5R)-Methyl-6-oxopipecolic acid ester (3a), prepared from L-α-aminoadipic acid, was chemoselectively reduced to the protected (5R)-methyl-6-hydroxypipecolic acid ester (4a), followed by treatment with L-cysteine methyl ester to give the linear key intermediate (5a) with the desired configuration. After deprotection of the ester moiety of 5a, the newly generated carboxylic acid group was intramolecularly condensed with the amino group at the thiazolidine ring using ethyl chloroformate in the presence of base to provide [5.7]-bicyclic compound (7a) with the desired configuration in excellent yield. Lastly, the methyl ester of 7a was hydrolyzed under alkaline conditions to afford 8a, a key intermediate for ER-40133.
一种新型拟肽双金属蛋白酶抑制剂 ER-40133 的关键中间体的高效合成工艺被开发出来。(由 L-α-氨基己二酸制备的(5R)-甲基-6-氧代联哌啶酸酯(3a)被化学选择性地还原成受保护的(5R)-甲基-6-羟基联哌啶酸酯(4a),然后用 L-半胱氨酸甲酯处理,得到具有所需构型的线性关键中间体(5a)。对 5a 的酯基进行脱保护处理后,在碱存在下使用氯甲酸乙酯将新生成的羧酸基团与噻唑烷环上的氨基进行分子内缩合,得到具有所需构型的[5.7]-双环化合物 (7a),收率极高。最后,在碱性条件下水解 7a 的甲酯,得到 ER-40133 的关键中间体 8a。