Synthesis of α, β-unsaturated dioxanes, dioxolanes and dioxepanes by trans-acetalisation of dimethylacetals with meso or C 2-symmetrical 1, 2-, 1, 3-and 1, 4-diols
L Lemiègre, F Lesetre, JC Combret, J Maddaluno
文献索引:Lemiegre, Loic; Lesetre, Fleur; Combret, Jean-Claude; Maddaluno, Jacques Tetrahedron, 2004 , vol. 60, # 2 p. 415 - 427
Several o-dibenzylic diols were prepared reacting organometallics with o-phthalaldehyde at room temperature in ether. The identity of the meso and C2-symmetrical (d, l) isomers as well as their ratio were determined by chiral gas chromatography. The meso and C2 (racemic) stereoisomeric diols were easily separated by flash chromatography on silica gel. A set of 18 α, β-unsaturated acetals were then prepared reacting those, as well as ...