乙醛酸乙酯 、 erythro-2-methyl-4-nitro-3-phenylbutyraldehyde 在
1,8-二氮杂双环[5.4.0]十一碳-7-烯 作用下,
以
甲苯 为溶剂,
反应 17.0h,
生成 (2S,3S,4S,5R)-ethyl-6-hydroxy-5-methyl-3-nitro-4-phenyltetrahydro-2H-pyran-2-carboxylate 、
(2S,3S,4S,5R)-ethyl-6-hydroxy-5-methyl-3-nitro-4-phenyltetrahydro-2H-pyran-2-carboxylate 、
(3R,4S)-ethyl-2-hydroxy-3-methyl-4-phenyl-3, 4-dihydro-2H-pyran-6-carboxylate 、 (3R,4S)-ethyl-2-hydroxy-3-methyl-4-phenyl-3, 4-dihydro-2H-pyran-6-carboxylate