The Hetero-Diels-Alder Addition of Sulfur Dioxide to 1-Fluorobuta-1,3-dienes: The Sofa Conformations Preferred by 6-Fluorosultines (6-Fluoro-3,6-dihydro-1,2-oxathiin-2-oxides) Enjoy Enthalpic and Conformational Anomeric Effects
作者:Elena Roversi、Rosario Scopelliti、Euro Solari、Raphaël Estoppey、Pierre Vogel、Pedro Braña、Bibiana Menéndez、José A. Sordo
DOI:10.1002/1521-3765(20020315)8:6<1336::aid-chem1336>3.0.co;2-r
日期:2002.3.15
(gem-disubstitution by sulfinyloxy and fluoro groups) effect, which is interpreted in terms of (lone pair) n(O1)-->sigma*(C-F) hyperconjugative interactions. This effect is strongest in the sofa conformers with a gauche arrangement of the sigma(O1,S2) and sigma(C6,F) bonds. The calculations suggest also that n(O1)-->sigma*(S2,O2'), pi*(S=O), and n(S2)-->sigma*(O1,C6) interactions intervene and affect the relative stability
(E)-和(Z)-1-氟丁1,3-二烯((E)-和(Z)-11),2-氟丁二烯(12),(E)-和(Z)-的反应活性已探究了对SO(2)的1-(氟亚甲基)-2-亚甲基环己烷((E)-和(Z)-13)并与(Z)-和(E)-1-(氟亚甲基)-2进行了比较-亚甲基-3,4-二氢萘((Z)-8和(E)-8)。与量子计算一致,12对SO(2)不反应(无环加成,仅聚合),而(E)-1-氟-1,3-二烯的反应比其(Z)异构体反应更快,从而给出相应的遵循异-Diels-Alder加成的endo(Alder规则)模式的6-氟磺胺类。与其它取代的二烯相反,在以氟二烯的增溶加成模式下,未观察到环丁砜。与计算结果一致,顺式-2-氟-3,4-氧杂噻吩并双环[4.4.0] dec-1(6),9-二烯-4-氧化物(顺式9,通过在动力学控制条件下将SO(2)加到(Z)-8中而获得的磺胺类化合物)采用一种沙发构象,其环的氧