The high-pressure Diels-Alder reaction between 2,5-dimethylfuran and d-galacto-3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-1-nitrohept-1-enitol led, after fractional crystallization from the crude product, to pure (2S,3R)-2-(endo-d-galacto-pentaacetoxypentyl)-1,4-dimethyl-3-exo-nitro-7-oxabicyclo[2.2.1]hept-5-ene. The structure was determined through a chemical route and by X-ray powder diffractometry. De-acetylation of the sugar side chain of this adduct caused the ring opening of the bicyclic system, followed by a tandem process of intramolecular nucleophilic additions, thus leading to new chiral bicyclic and tricyclic ethers.
在高压Diels-Alder反应中,
2,5-二甲基呋喃与d-galacto-3,4,5,6,7-五-O-乙酰基-1,2-去氧-1-硝基庚-1-烯醇反应,经过从粗产物中进行分馏结晶,得到纯净的(2S,3R)-2-(endo-d-galacto-五乙酰氧基戊基)-1,4-二甲基-3-exo-硝基-7-氧双环[2.2.1]庚-5-烯。其结构通过
化学途径和X射线粉末衍射法确定。该加合物糖侧链的去乙酰化导致了双环体系的开环,随后发生了分子内亲核加成的串联反应,从而生成新的手性双环和三
环醚。