EPC synthesis of 5-substituted 2-oxo-cyclopentanecarboxylates via conjugate addition of cuprates to asymmetric shielded 2-oxo-cyclopentenecarboxylates
                                
                                    
                                        作者:Ernst Urban、Guido Knühl、Günter Helmchen                                    
                                    
                                        DOI:10.1016/0040-4039(95)01537-r
                                    
                                    
                                        日期:1995.10
                                    
                                    te 2 with camphor derived concave alcohols 1n and 1x and by subsequent introduction of a double bond via phenylselenides. Diastereoselective conjugate addition of equimolar amounts of mixed cuprates at −78 °C and deprotection by ethanolysis gave enantiomerically pure 5-substituted 2-oxo-cyclopentanecarboxylates 13–18 and ent-13–18, valuable as chiral building blocks in natural product synthesis.
                                    通过将2-氧代-
环戊烷羧酸酯2与
樟脑衍生的凹型醇1n和1x进行酯交换并随后通过苯基
硒化物引入双键来制备不对称的被保护的2-氧代-
环戊烯羧酸酯6n和6x。在-78°C上等摩尔量的混合
铜酸盐的非对映选择性共轭物加成,并通过
乙醇解脱保护得到对映体纯的5取代的2-氧代-
环戊烷羧酸酯13-18和ent - 13-18,在
天然产物合成中作为手性结构单元很有价值。