Synthesis and ring opening reactions of 2-glyco-1,4-dimethyl-3-nitro-7-oxabicyclo[2.2.1]hept-5-enes |
| |
Authors: | Noelia Araújo José A Serrano |
| |
Institution: | Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain |
| |
Abstract: | The high-pressure asymmetric Diels-Alder reactions of d-galacto- (1a) and d-manno-3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-1-nitrohept-1-enitol (1b) with 2,5-dimethylfuran (2) afforded mixtures of cycloadducts, from which the (2S,3R)-3-exo-nitro (3a and 3b), (2R,3S)-3-exo-nitro (4a and 4b), and (2R,3S)-1′,2′,3′,4′,5′-penta-O-acetyl-1′-C-(1,4-dimethyl-3-endo-nitro-7-oxabicyclo2.2.1]hept-5-en-2-exo-yl)-d-galacto-pentitol (5b) were isolated pure. Deacetylation of these compounds led to new chiral mono-, bi-, and tricyclic ethers, being their asymmetric centers arising from the chiral inductor used in the cycloaddition reaction. A ring opening mechanism through a 1-nitro-1,3-cyclohexadiene intermediate has been proposed. |
| |
Keywords: | Asymmetric synthesis Carbohydrate nitroalkenes Chiral 7-oxanitronorbornenes Diels-Alder reaction Oxygen heterocycles Ring opening reactions |
本文献已被 ScienceDirect 等数据库收录! |
|