Stereoselective Synthesis of 1,3-Disaccharides through Diels-Alder Reactions: Part 2[ 1 ]: Convenient Protecting Groups for Heterodienes and Conformational Evaluations |
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| Authors: | Gabriele Gabrielli Fabrizio Melani Sara Bernasconi Carlotta Lunghi Barbara Richichi Patrick Rollin |
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| Institution: | 1. Dipartimento di Chimica Organica , Universita' di Firenze , via della Lastruccia 13, Sesto Fiorentino, FI, I-50019, Italy;2. Dipartimento di Scienze Farmaceutiche , Universita' di Firenze , via Ugo Schiff 3, Sesto Fiorentino, FI, I-50019, Italy;3. ICOA, UMR Sciences , BP 6759, rue de Chartres, 45067, Orléans Cedex 2, France |
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| Abstract: | Improved synthesis of 1,3-disaccharides, obtained diastereomerically pure by 4+2] hetero cycloadditions between glycals and α -thiono-β -keto-δ -lactones, has been reported. The choice of appropriate protecting groups for β -keto-δ -lactones, stable under cycloaddition conditions employed, sensibly shortened the synthesis of heterodienic precursors. The first example of a β -oxy-imino-δ -lactone synthesized from β -keto-δ -lactones was also reported. Molecular modeling and conformational evaluations about the cycloaddition features allowed tentatively rationalizing the experimental results. |
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| Keywords: | Disaccharides Diels-alder Stereoselective synthesis Conformational studies |
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