Studies on Horner-Wadsworth-Emmons reaction in base sensitive ketones: Synthesis of (−)-mitsugashiwalactone and formal synthesis of (+)-iridomyrmecin, (−)-isoiridomyrmecin and (+)-teucriumlactone
作者:A Nangia、G Prasuna
DOI:10.1016/0040-4020(96)00023-3
日期:1996.3
The effect of different bases in promoting Horner-Wadsworth-Emmons (HWE) reaction on enolisable cyclopentanones is investigated. NaH is found to be suitable for the intermolecular reaction and DBU/LiCl is optimal for the intramolecular variation. The HWE approach is employed for the enantioselective synthesis of iridoid cyclopentapyranones of type-I (4,16,52) and type-II (5,36).
Catalytic Iron-Mediated Triene Carbocyclizations: Stereoselective Five-Membered Ring Forming Carbocyclizations
作者:James M. Takacs、Young-Chan Myoung、Lawrence G. Anderson
DOI:10.1021/jo00102a016
日期:1994.11
The full details of investigations into the regiochemistry and stereochemistry of iron-catalyzed carbocyclizations of 2,7,9-decatriene derivatives to form five-membered carbocyclic ring systems are described. The roles of the allylic substituent, the alkene geometry, diene substitution, and the influence of resident stereogenic centers incorporated in the tether chain connecting the reacting 1,3-diene and alkene subunits are discussed.