Diethyl 2-[cyano(toluene-4-sulfinyl)methylene]propanedioate and its Diels-Alder adduct with cyclopentadiene

• Published in: Acta crystallographica. Section C, Crystal structure communications Crystal structure communications, 2001-11, Vol.57 (11), p.1313-1315
• Main Authors: Toscano, Rubén A., Hernández-Ortega, Simón, Ortiz, Benjamín, Sánchez-Obregón, Rubén, Walls, Fernando, Yuste, Francisco
• Format: Article
• Language: English
• Subjects: Aliphatic, non-condensed and condensed benzenic, and alicyclic compounds; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Organic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0108-2701; 1600-5759
• DOI: 10.1107/S0108270101012951

The thermal Diels–Alder cyclo­additon reaction of diethyl 2‐­[cyano­(toluene‐4‐sulfinyl)­methyl­ene]­propane­dioate, C16H17­NO5S, with cyclo­penta­diene gave the pure racemates of two of the four possible diastereomers, with a complete π‐facial selectivity and a high (80:20) endo/exo‐sulfinyl selectivity. X‐ray diffraction studies of diethyl 2‐[cyano­(toluene‐4‐sulfinyl)­methyl­ene]­propane­dioate and the major isomer of the cyclo­addition product, namely diethyl 3‐cyano‐3‐(toluene‐4‐sulfinyl)­bi­cyclo­[2.2.1]­hepta‐5‐ene‐2,2‐di­carboxyl­ate, C21H23­NO5S, reveal that the conformation of the substituents on the acrylo­nitrile moiety produces both steric and electronic effects, which affect the stereoselectivity of the reaction.