Sodium salt of 3-hydroxymethylenetetrahydro-2H-pyran-2-one (V), obtained by Claisen condensation of δ-valerolactone with ethyl formate, was converted into its sulfonates and carboxylates IV, VII - X, which were obtained either as pure E-isomers or as mixtures of E- and Z-isomers; the mixtures were chromatographically separated. Substitution reaction of α-tosyloxymethylene lactones II, III and IV with aromatic thiols, azide anion, secondary amines and sodium enolates XI, XII and V was studied. The stereochemical outcome of this substitution is discussed from the viewpoint of mechanism of nucleophilic vinylic substitution (SNV).
通过
δ-戊内酯和
乙酸乙酯的克莱森缩合反应获得了3-羟甲基四氢-
2H-吡喃-2-酮的钠盐(V),并将其转化为
磺酸盐和
羧酸盐IV、VII-X,这些化合物可以作为纯的E异构体或E和Z异构体的混合物得到;混合物经过色谱分离。研究了α-对
甲苯磺酰氧亚
甲基内酯II、III和IV与芳香
硫醇、
叠氮阴离子、二级胺和
钠烯醇酸盐XI、XII和V的取代反应。从亲核烯丙基取代(SNV)的机理角度讨论了这种取代反应的立体
化学结果。