Phenylglycine 1 as a representative of natural resourceful a-amino acid was modified by reduction and protection of functional group to afford the amino alcohol as a chiral building block 3. A new chiral compound, the...Phenylglycine 1 as a representative of natural resourceful a-amino acid was modified by reduction and protection of functional group to afford the amino alcohol as a chiral building block 3. A new chiral compound, the chiral building block/spiro-cyclopropane derivative containing four stereogenic centers, compound 7, has been obtained in 52% yield with de≥98% via the tandem double Michael addition/internal nucleophilic substitution under mild condition of 5-l-menthyloxy-3-bromo-2-(5H)-furanone 4 with the nucleophilic reagent, the amino alcohol 3. The new chiral compound 7 is identified on the basis of its analytical data and spectroscopic data, such as UV, IR, 1H NMR, 13C NMR, MS and elementary analysis. The absolute configuration of the interesting spiro-cyclopropanes 7 was established by X-ray crystallography. This result can provide new route and method for the introduction of chiral building block and the important synthetic strategy in synthesis of some complex molecules containing展开更多
The asymmetric reaction of the chiron 2(5H)-furanones (4a-4c) with the Homer-Emmons reagents (5a-5b) has been investigated. The newly chiral organophosphorus derivatives 6 and 7 were obtained using the phosphoryl-stab...The asymmetric reaction of the chiron 2(5H)-furanones (4a-4c) with the Homer-Emmons reagents (5a-5b) has been investigated. The newly chiral organophosphorus derivatives 6 and 7 were obtained using the phosphoryl-stabilized carbanion as a building block in DMSO under mild conditions. Through the asymmetric introduction, the Horner-Emmons reagent could be transformed to a chiral building block to afford the novel functionalized phosphorus derivatives. The structures of the synthesized compounds 6 and 7 were identified on the basis of their elementary and spectroscopic data, such as IR, 1H NMR, 13C NMR, MS and X-ray crystallography. These results provided a valuable approach to the synthesis of potentially interesting chiral organophosphorus derivatives and probing their biological activities.展开更多
A concise five-step approach to indolizidinones 10 and 11,two advanced intermediates for the asymmetric synthesis of polyhydroxylated indolizidine alkaloids,has been developed by using N-Cbz pyrrolidin-2-yl pyridin-2-...A concise five-step approach to indolizidinones 10 and 11,two advanced intermediates for the asymmetric synthesis of polyhydroxylated indolizidine alkaloids,has been developed by using N-Cbz pyrrolidin-2-yl pyridin-2-yl sulfide 13 as the chiral building block.The method features a SmI2-mediated coupling of sulfide 13 with functionalized aldehyde 14 and a tandem N-deprotection-lactamization,which constitutes a stepwise "2 + 4" annulation method for the construction of the indolizidinone ring system of 12a.展开更多
A practical synthesis of (R)-4-(benzyloxy)-3-methylbutanenitrile, a potential chiral building block, from the corresponding a-keto ester in high yield and large scale was presented.
A bioactive derivative of a natural diarylheptanoid containing a 1,3-anti diol motif was synthesized with the oxygen-carrying stereogenic centers taken from an enantiopure epoxy chiral building block derived from inex...A bioactive derivative of a natural diarylheptanoid containing a 1,3-anti diol motif was synthesized with the oxygen-carrying stereogenic centers taken from an enantiopure epoxy chiral building block derived from inexpensive and readily available D-glucolactone.展开更多
Two chiral building blocks 1 and 2 for anti-and syn-1, 3-diols has been achieved in 8 steps and 7 steps respectively, starting from the readily available and inexpensive D (+)-xylose 3.
Compounds 4 and 5 which were new selectively protected and multifunctional chiral C 4 building blocks were prepared conveniently from commercially available D erythorbic acid in no more than three steps with satisfied...Compounds 4 and 5 which were new selectively protected and multifunctional chiral C 4 building blocks were prepared conveniently from commercially available D erythorbic acid in no more than three steps with satisfied yields. Since compound 4 and compound 5 are densely functionalized and rich in stereochemistry, they are useful chiral building blocks in asymmetric synthesis.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 29672004).
文摘Phenylglycine 1 as a representative of natural resourceful a-amino acid was modified by reduction and protection of functional group to afford the amino alcohol as a chiral building block 3. A new chiral compound, the chiral building block/spiro-cyclopropane derivative containing four stereogenic centers, compound 7, has been obtained in 52% yield with de≥98% via the tandem double Michael addition/internal nucleophilic substitution under mild condition of 5-l-menthyloxy-3-bromo-2-(5H)-furanone 4 with the nucleophilic reagent, the amino alcohol 3. The new chiral compound 7 is identified on the basis of its analytical data and spectroscopic data, such as UV, IR, 1H NMR, 13C NMR, MS and elementary analysis. The absolute configuration of the interesting spiro-cyclopropanes 7 was established by X-ray crystallography. This result can provide new route and method for the introduction of chiral building block and the important synthetic strategy in synthesis of some complex molecules containing
基金Project supported by the National Natural Science Foundation of China(No.29672004).
文摘The asymmetric reaction of the chiron 2(5H)-furanones (4a-4c) with the Homer-Emmons reagents (5a-5b) has been investigated. The newly chiral organophosphorus derivatives 6 and 7 were obtained using the phosphoryl-stabilized carbanion as a building block in DMSO under mild conditions. Through the asymmetric introduction, the Horner-Emmons reagent could be transformed to a chiral building block to afford the novel functionalized phosphorus derivatives. The structures of the synthesized compounds 6 and 7 were identified on the basis of their elementary and spectroscopic data, such as IR, 1H NMR, 13C NMR, MS and X-ray crystallography. These results provided a valuable approach to the synthesis of potentially interesting chiral organophosphorus derivatives and probing their biological activities.
基金the National Natural Science Foundation of China (20832005)the National Basic Research Program (973 Program) of China (2010CB833200) for financial support
文摘A concise five-step approach to indolizidinones 10 and 11,two advanced intermediates for the asymmetric synthesis of polyhydroxylated indolizidine alkaloids,has been developed by using N-Cbz pyrrolidin-2-yl pyridin-2-yl sulfide 13 as the chiral building block.The method features a SmI2-mediated coupling of sulfide 13 with functionalized aldehyde 14 and a tandem N-deprotection-lactamization,which constitutes a stepwise "2 + 4" annulation method for the construction of the indolizidinone ring system of 12a.
文摘A practical synthesis of (R)-4-(benzyloxy)-3-methylbutanenitrile, a potential chiral building block, from the corresponding a-keto ester in high yield and large scale was presented.
基金Project supported by the National Basic Research Program of China (973 Program) (No. 2010CB833200), the National Natural Science Foundation of China (Nos. 21032002, 20921091, 20672129, 20621062, 20772143) and the Chinese Academy of Sciences ("Knowledge Innovation", Nn. KJCX2.YW.H08)
文摘A bioactive derivative of a natural diarylheptanoid containing a 1,3-anti diol motif was synthesized with the oxygen-carrying stereogenic centers taken from an enantiopure epoxy chiral building block derived from inexpensive and readily available D-glucolactone.
文摘Two chiral building blocks 1 and 2 for anti-and syn-1, 3-diols has been achieved in 8 steps and 7 steps respectively, starting from the readily available and inexpensive D (+)-xylose 3.
文摘Compounds 4 and 5 which were new selectively protected and multifunctional chiral C 4 building blocks were prepared conveniently from commercially available D erythorbic acid in no more than three steps with satisfied yields. Since compound 4 and compound 5 are densely functionalized and rich in stereochemistry, they are useful chiral building blocks in asymmetric synthesis.