γ-substituted β,γ-unsaturated-α-ketoesters with acetaldehyde, afforded the corresponding lactals, which were subjected to oxidation and stereocontrolled hydrogenation to provide 3,5,6-trisubstituted and 4,6-disubstituted tetrahydropyran-2-ones with excellent enantioselectivities.
用二芳基脯
氨醇醚催化的迈克尔加成反应,然后将3-甲基-2-氧代丁-3-烯酸
乙酯与醛环合,然后将γ-取代的β,γ-不饱和-α-
酮酸酯与
乙醛环合,得到相应的
乳酸酯,将其乳化。进行氧化和立体控制的氢化反应,得到具有优异对映选择性的3,5,6-三取代和4,6-二取代的
四氢吡喃-2-酮。