leading to the title products as single diastereomers with enantiomeric excesses from 86% up to 97%. Alkyl 4,5-dihydrofuran-2-carboxylates can be efficiently obtained via an enantioselective organocatalyzed consecutive reaction between α-keto esters and (Z)-(2-chloro-2-nitroethenyl)benzenes. The overall sequence combines a (R,R)-TUC-catalyzed Michael addition with a DABCO-promoted intramolecular O-alkylation
献给教授迪特尔·恩德斯在他70之际个生日 抽象的 通过α-
酮酸酯和(Z)-(2-
氯-2-
硝基乙烯基)苯之间的对映选择性有机催化连续反应,可以有效地获得4,5-二氢
呋喃-2-
羧酸烷基酯。整个序列结合了(R,R)-TUC催化的迈克尔加成与
DABCO促进的分子内O-烷基化,得到标题产物,为单一非对映异构体,对映体过量从86%到97%。 通过α-
酮酸酯和(Z)-(2-
氯-2-
硝基乙烯基)苯之间的对映选择性有机催化连续反应,可以有效地获得4,5-二氢
呋喃-2-
羧酸烷基酯。整个序列结合了(R,R)-TUC催化的迈克尔加成与
DABCO促进的分子内O-烷基化,得到标题产物,为单一非对映异构体,对映体过量从86%到97%。