promotes the reaction of ammonium enolates derived from arylacetic acids with N‐tosyl‐α,β‐unsaturated ketimines, thus giving dihydropyridones with high diastereo‐ and enantiocontrol (see scheme). These products readily undergo N‐ to C‐sulfonyl photoisomerization and are derivatized to afford stereodefined piperidines and tetrahydropyrans.
苯并四
咪唑(1)促进了从芳酸中衍生出来的烯醇
铵盐与N-
甲苯磺酰基-α,β-不饱和酮
亚胺的反应,从而使
二氢吡啶酮具有非对映异构和对映异构控制性(见方案)。这些产品容易进行N-至C-磺酰基的光异构化,并衍生化得到立体定义的
哌啶和
四氢吡喃。