Lewis Base Catalyzed Enantioselective Aldol Addition of Acetaldehyde-Derived Silyl Enol Ether to Aldehydes
作者:Scott E. Denmark、Tommy Bui
DOI:10.1021/jo0517500
日期:2005.11.1
Chiral phosphoramide catalyzed-enantioselective aldol addition of an acetaldehyde-derived trialkylsilyl enol ether to aromatic aldehydes provides protected aldol products in good yields with good to excellent enantioselectivities. Preliminary studies show that the aldolization intermediate (a chlorohydrin adduct) can be trapped with tert-butyl isocyanide to form an α-hydroxy lactone with good selectivity
Stereoselective synthesis of cis- or trans-2,4-disubstituted butyrolactones from Wynberg lactone
作者:Ashok Ganta、Julia L. Shamshina、Lauren R. Cafiero、Timothy S. Snowden
DOI:10.1016/j.tet.2012.04.107
日期:2012.7
(R)-Wynberg lactone was used to prepare various asymmetric 2,4-disubstituted butyrolactones in three to four steps. Attainment of any possible stereoisomer, based upon commencement from (R)- or (S)-4-trichloromethyl-2-oxetanone, and the capacity to install disparate substituents at C2 make this approach particularly versatile.