Synthesis and Cycloaddition Reactions of Ethyl (<i>E</i>)-3-Aryl-2-(nonafluorobutyl)sulfonyl-2-propenoates
作者:Olaf Menke、Elke Steinhuber、Antonio García Martínez、L. R. Subramanian、Michael Hanack
DOI:10.1055/s-1994-25683
日期:——
Ethyl (nonafluorobutyl)sulfonylacetate (2) reacts stereo-selectively with substituted benzaldehydes 3 affording (E)-3-aryl-2-(nonafluorobutyl)sulfonyl-2-propenoates (E)-4, which are good dienophiles. The addition to cyclopentadiene yields exclusively the exo-products 8.
Synthesis and Cycloaddition Reactions of Ethyl 3-Aryl-2-(perfluoroalkanesulfonyl)propenoates – A Revised Stereochemistry of the Cyclopentadiene Adducts
3-aryl-2-(perfluoroalkanesulfonyl)propenoates were prepared by the Knoevenagel reaction from various aldehydes and ethyl (trifluoromethanesulfonyl)acetate or ethyl (nonafluorobutanesulfonyl)acetate. These deactivated olefins were used in Diels–Aldercycloadditionreactions with cyclopentadiene. The reactions occurred at roomtemperature to give [4+2] cycloadducts as racemates. The endo stereochemistry of the carboxylic
3-芳基-2-(全氟烷磺酰基)丙烯酸乙酯是通过各种醛和(三氟甲磺酰基)乙酸乙酯或(九氟丁烷磺酰基)乙酸乙酯的Knoevenagel反应制备的。这些失活的烯烃用于与环戊二烯的 Diels-Alder 环加成反应。反应在室温下发生,得到 [4+2] 环加合物作为外消旋物。NOE 实验和 X 射线分析明确指定了羧酸酯和芳基的内立体化学。