Organic Chemistry: Current Research
Open Access
ISSN: 2161-0401
+44 1478 350008
ISSN: 2161-0401
+44 1478 350008
Pierre Vogel
Swiss Institute of Technology in Lausanne, Switzerland
Posters & Accepted Abstracts: Organic Chem Curr Res
After burning dry grass and wood that produces CO2, man discovered Ca. 8000 years ago in Sicily, that burning sulfur in jars lead to food and beverages preservation. Although SO2 has been with us for very long its use in organic chemistry has led thus far to very few applications. We have invented a new organic chemistry based on the hetero-Diels-Alder and heteroene- reactions of SO2. The catalyzed hetero-Diels-Alder reaction of SO2 leads to unstable sultines which are formed faster than the more stable isomeric sulfolenes known since 1914. Using 1-alkoxy or 1-silyloxy-1, 3-dienes, the sultines are not seen at low temperature, but are formed as intermediates that are ionized into the corresponding zwitterions (Umpolung with SO2). The latter react with electron-rich alkenes giving the corresponding silyl sulfinates. After desilylation, retro-ene elimination of SO2 the ?², ï§-unsaturated sulfinic acids generate polypropionate fragments 5 that contain up to 3 contiguous stereogenic centers, this in one-pot procedures. The new reaction cascade has led to very efficient (fewer steps) total, asymmetric syntheses of Ryfamycin S, Baconipyrone, and Apoptolidin A, and the first (and very short) total synthesis of (-)-Dolabriferol. Polypropionate fragments containing up to ten contiguous stereogenic centers have been obtained in a few steps. Our reaction cascade permits the onepot, four component synthesis of polyfunctional sulfones and sulfonamides. New reagents for the silylation of hydroxyl groups of unstable aldol, for the selective silylation of carbohydrates, phenol and carboxylic acid have been invented also, as well as a new one-pot direct amidification of carboxylic acids.
Email: pierre.vogel@epfl.ch