Alkylation of diethyl 3 oxoglutarate monoanion by 4 bromobutene to produce enone diester 3, subsequent alkylation of 3 with 4 bromo 1 butene using K 2CO 3 and a catalytic amount of NaI in the mixed solvent afforded di...Alkylation of diethyl 3 oxoglutarate monoanion by 4 bromobutene to produce enone diester 3, subsequent alkylation of 3 with 4 bromo 1 butene using K 2CO 3 and a catalytic amount of NaI in the mixed solvent afforded dienone diester 4, which underwent decarboxylative hydrolysis when treated with 15% KOH in methanol under refluxing to provide dienone 5. The dienone afforded 2,8 dimethyl 1,7 dioxaspiroundecane 1 in good yield and high purity via an oxymercuration cyclisation reduction sequence.展开更多
R ) and ( S ) (2 benzyloxyethyl)oxirane 1 were prepared from ( S ) and ( R ) aspartic acid by modification of the procedure described by Rapoport. Aspartic acid was converted into bromosuccinic acid 2 by treatment wit...R ) and ( S ) (2 benzyloxyethyl)oxirane 1 were prepared from ( S ) and ( R ) aspartic acid by modification of the procedure described by Rapoport. Aspartic acid was converted into bromosuccinic acid 2 by treatment with sodium nitrite/potassium bromide/sulfuric acid,the diacid 2 was then reduced with freshly prepared boron trifluoride ethyl ether complex to bromodiol 3, which was further treated with sodium hydride and benzylbromide/TBAI(tetrabutylammonium iodide) to afford (2 benzyloxyethyl)oxirane. This procedure has shown the good yield, mild condition and excellent enantiomeric purity of the product.展开更多
文摘Alkylation of diethyl 3 oxoglutarate monoanion by 4 bromobutene to produce enone diester 3, subsequent alkylation of 3 with 4 bromo 1 butene using K 2CO 3 and a catalytic amount of NaI in the mixed solvent afforded dienone diester 4, which underwent decarboxylative hydrolysis when treated with 15% KOH in methanol under refluxing to provide dienone 5. The dienone afforded 2,8 dimethyl 1,7 dioxaspiroundecane 1 in good yield and high purity via an oxymercuration cyclisation reduction sequence.
文摘R ) and ( S ) (2 benzyloxyethyl)oxirane 1 were prepared from ( S ) and ( R ) aspartic acid by modification of the procedure described by Rapoport. Aspartic acid was converted into bromosuccinic acid 2 by treatment with sodium nitrite/potassium bromide/sulfuric acid,the diacid 2 was then reduced with freshly prepared boron trifluoride ethyl ether complex to bromodiol 3, which was further treated with sodium hydride and benzylbromide/TBAI(tetrabutylammonium iodide) to afford (2 benzyloxyethyl)oxirane. This procedure has shown the good yield, mild condition and excellent enantiomeric purity of the product.
