Glyoxylic Acid versus Ethyl Glyoxylate for the Aqueous Enantioselective Synthesis of α-Hydroxy-γ-Keto Acids and Esters by the N-Tosyl-(S a)-binam-l-prolinamide-Organocatalyzed Aldol Reaction
作者:Gabriela Guillena、Carmen Nájera、Enrique Gómez-Bengoa、Fernando Moles
DOI:10.1055/s-0034-1379546
日期:——
ers; however, the reaction between 4-phenylcyclohexanone and ethyl glyoxylate gave the corresponding syn,syn-product as the major diastereoisomer. N-Tosyl-(S a)-binam-l-prolinamide is an efficient catalyst for the aqueous aldol reaction between ketones and glyoxylic acid, as the monohydrate or as an aqueous solution, or a 50% toluene solution of ethyl glyoxylate. These reactions led to the formation
摘要 N-甲苯磺酰基-(S a)-联氨-1-脯氨酰胺是一种有效的催化剂,用于酮和乙醛酸之间的含水羟醛反应,作为一水合物或水溶液或乙醛酸乙酯的50%甲苯溶液。这些反应导致以高水平的非对映选择性和对映选择性(高达97%ee)形成手性α-羟基-γ-酮基羧酸和酯,主要提供抗羟醛产物。仅环戊酮和环己烷-1,4-二酮可提供近1:1的顺/反-非对映异构体混合物。然而,4-苯基环己酮与乙醛酸乙酯之间的反应产生了相应的syn,syn产品为主要的非对映异构体。 N-甲苯磺酰基-(S a)-联氨-1-脯氨酰胺是一种有效的催化剂,用于酮和乙醛酸之间的含水羟醛反应,作为一水合物或水溶液或乙醛酸乙酯的50%甲苯溶液。这些反应导致以高水平的非对映选择性和对映选择性(高达97%ee)形成手性α-羟基-γ-酮基羧酸和酯,主要提供抗羟醛产物。仅环戊酮和环己烷-1,4-二酮可提供近1:1的顺/反-非对映异构体混合物。然而,4-