81787-39-5Relevant articles and documents
Synthesis of (E)-α,β-unsaturated esters with total or high diastereoselectivity from α,β-epoxyesters
Concellon, Jose M.,Bardales, Eva
, p. 189 - 191 (2007/10/03)
Chemical equation presented High stereoselective β-elimination in 2,3-epoxyesters 1 was achieved using samarium diiodide, yielding α,β-unsaturated esters 2, in which the C=C bond is di-, tri- or tetrasubstituted. The starting compounds 1 are easily prepared by reaction of the corresponding lithium enolates of a-chloroesters with aldehydes or ketones at -78 °C. The influence of the reaction conditions and the structure of the starting compounds in the stereoselectivity of the β-elimination reaction is also discussed.
Sequential elimination-reduction reactions promoted by samarium diiodide: Synthesis of 2,3-dideuterioesters or -amides
Concellon, Jose M.,Rodriguez-Solla, Humberto
, p. 4266 - 4271 (2007/10/03)
A facile and general sequential elimination/reduction process promoted by samarium diiodide provides an efficient method for synthesizing saturated esters or amides 3 from readily available starting materials. The reaction involves a β-elimination of the starting 2-halo-3-hydroxyesters or -amides 1 and subsequent 1,4-reduction of the obtained α,β-unsaturated esters or amides in the presence of H2O. When D2O is used instead of H2O, 2,3-dideuterioesters or -amides 4 are isolated. A mechanism is proposed to account for this synthesis.
1-alkoxycarbonylalkylidenetriphenylarsoranes: Preparation and reactions
Castells,Lopez-Calahorra,Yu
, p. 13765 - 13774 (2007/10/02)
The higher homologues of the well-studied alkoxycarbonylmethylenetriphenylarsonium ylide (3, R=H) can be easily obtained through the sequence: a), preparation of alkyl 2-trifloxyalkanoates (1); b), reaction between these trifloxyderivatives and triphenylphosphine to give 1-alkoxycarbonylalkyltriphenylarsonium triflates (2); and c), basic treatment of the triphenylarsonium triflates (2) with alumina-supported potassium fluoride to give 1-alkoxycarbonylalkyledenetriphenylarsonium ylides (3). These higher homologues of (3, R=H) react with aromatic aldehydes in good to excellent yields, and give rise to synthetically interesting 'coupling' and cyclopropanation reactions.
