申请人:Keystone BioMedical, Inc.
公开号:US06063919A1
公开(公告)日:2000-05-16
A process for the synthesis of an Exochelin comprising the steps of generating L-N-[(2-benzyloxy-(benzoyl)] serine or L-N-[2-benzyloxy (benzoyl)] threonine, creating L-N-t-Boc-.epsilon.-hydroxynorleucine and reacting same to produce L-N-Boc-.epsilon.-bromonorleucine trimethylsilylethyl ester, providing a dicarboxylic acid and forming an O-benzyl methyl hydroxamate from the dicarboxylic acid, coupling the O-benzyl methyl hydroxamate with the L-N-Boc-.epsilon.-bromonorleucine trimethylsilylethyl ester to give an L-N.sup.2 -Boc-N.sup.6 -methyl,N.sup.6 -(benzyloxy) lysine 2-trimethylsilylethyl ester which incorporates the dicarboxylic acid as modified above, removing the N-tert-butoxycarbonyl protecting group from the L-N.sup.2 -Boc-N.sup.6 -methyl, N.sup.6 -(benzyloxy) lysine 2-trimethylsilylethyl ester to yield a substituted lysine, and coupling the same with the L-N-[2-benzyloxy (benzoyl) serine or -threonine to yield a 2-trimethyl silylethyl ester of dibenzyl Exochelic acid, transforming the 2-trimethyl silylethyl ester of dibenzyl Exochelic acid to dibenzyl Exochelic acid, preparing benzyl epi-cobactin, forming an ester bond between the dibenzyl Exochelic acid and benzyl epi-cobactin to form an intermediate, and, hydrogenolytically removing three benzyl groups from said intermediate, resulting in the synthesized Exochelin. More particularly, a synthesis for Exochelin 786SM (R) is disclosed wherein the dicarboxylic acid is suberic acid and the serine form is utilized.
合成Exochelin的过程包括以下步骤:生成L-N-[(2-苄氧基-(苯甲酰)]丝氨酸或L-N-[2-苄氧基(苯甲酰)]缬氨酸,生成L-N-t-Boc-.epsilon.-羟基异亮氨酸并将其与L-N-Boc-.epsilon.-溴异亮氨酸三甲基硅基乙酯反应,提供二羧酸并从二羧酸制备O-苄基甲基羟肟,将O-苄基甲基羟肟与L-N-Boc-.epsilon.-溴异亮氨酸三甲基硅基乙酯偶联以得到L-N.sup.2 -Boc-N.sup.6 -甲基,N.sup.6 -(苄氧基)赖氨酸2-三甲基硅基乙酯,去除L-N.sup.2 -Boc-N.sup.6 -甲基,N.sup.6 -(苄氧基)赖氨酸2-三甲基硅基乙酯中的N-叔丁氧羰保护基以得到取代赖氨酸,将其与L-N-[2-苄氧基(苯甲酰)丝氨酸或缬氨酸偶联以得到二苄基Exochelic酸的2-三甲基硅基乙酯,将二苄基Exochelic酸的2-三甲基硅基乙酯转化为二苄基Exochelic酸,制备苄基环境素,形成二苄基Exochelic酸和苄基环境素之间的酯键以形成中间体,通过氢解去除中间体中的三个苄基基团,从而得到合成的Exochelin。特别地,揭示了Exochelin 786SM (R)的合成,其中二羧酸是琥珀酸,丝氨酸形式被利用。