334947-63-6Relevant academic research and scientific papers
Stereoselectivity control in Diels-Alder reactions of 4-thiosubstituted 5-alkoxyfuranones: Synthesis and reactivity of enantiopure 4-sulfinyl and sulfonyl 5-(l-menthyloxy)furan-2(5H)-ones
Ruano, Jose L. Garcia,Bercial, Fernando,Fraile, Alberto,Castro, Ana M. Martin,Martin, M. Rosario
, p. 4737 - 4752 (2000)
The synthesis of enantiomerically pure (S)-4-phenylsulfinyl- and 4-phenylsulfonyl-(5S)-5-(l-menthyloxy)furan-2(5H)-ones 5a and 6 and (5R)-5-(l-menthyloxy)-4-phenylsulfonylfuran-2(5H)-one 8 and the study of their reactions with cyclopentadiene are described. The sulfur substituents at C-4 modify (sulfone 8, anti/syn = 78/22) and invert (sulfoxide 5a and sulfone 6, anti/syn≈27/73) the trend imposed by C-5 on the π-facial selectivity and the syn-adducts become the favoured ones. The endo or exo approach mode is favoured for anti (endo/exo ratio ranging between 26 and 5) or syn (exo/endo ratio ranging between 4.5 and 2.3) attack, respectively.
