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
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.
