Preparation of α,α-Disubstituted α-Amino Acid Derivatives via Alkyl Addition to α-Oxime Esters with Organozinc Species
作者:Michiharu Mitani、Yasunori Tanaka、Akihiko Sawada、Ayuko Misu、Yoshihiro Matsumoto
DOI:10.1002/ejoc.200700929
日期:2008.3
α-amino ester. Treatment of the oxime derivative prepared from methyl 5-bromo-2-oxopentanoate with the trialkylzincate gave an α-alkyl proline derivative via the addition reaction followed by the intramolecular attack upon a bromine-bearing carbon. The reaction of ethyl 4-oxo-2-pentynoate with hydroxylamine formed an isoxazole derivative by way of the intramolecular attack of an in situ-generated oxime
通过用羟胺处理乙炔二羧酸酯或α-酮酯制备的α-肟酯衍生物通过路易斯酸促进的与三烷基锌酸盐或二烷基锌试剂的反应,C-烷基化为肟基团的C=N键。在 Pd-C 催化剂的存在下,由此获得的加合物的 O-N 键在氢解下还原裂解,得到 α-氨基酯。用锌酸三烷基酯处理由 5-溴-2-氧代戊酸甲酯制备的肟衍生物,通过加成反应得到 α-烷基脯氨酸衍生物,然后分子内攻击含溴的碳。4-氧代-2-戊酸乙酯与羟胺的反应通过原位生成的肟对羰基的分子内攻击形成异恶唑衍生物。从这种异恶唑衍生物,2-氨基-4-氧代-2-戊烯酸乙酯通过Pd-C催化的氢解得到。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)