Mg/MeOH/Et3N to a thio-substituted indolizidinone 3. This method was also extended to a methyl-substituted diene 16, which stereoselectively provided the cis-2,6-disubstitutedproduct 17. Further synthetic transformations yielded indolizidinones 20–24, including a formal synthesis of the natural product monomorine I.
氮杂-Diels-Alder反应产物2易于转化为四氢
吡啶衍生物6,但其N-苄基在各种条件下均难以裂解。另一方面,N-
甲苯磺酰基α,β-不饱和酯14通过Mg / MeOH / Et 3 N一步转化为
硫代取代的
吲哚并二酮3。该方法也扩展到了甲基取代的二烯16,它立体选择性地提供了顺式-2,6-二取代的产物17。进一步的合成转化产生了indolizidinones 20 – 24,包括
天然产物monomorine I的正式合成。