Organocatalytic Enantio- and Diastereoselective Construction of <i>syn</i>-1,3-Diol Motifs via Dynamic Kinetic Resolution of In Situ Generated Chiral Cyanohydrins
syn-1,3-dioxanes as protected 1,3-diols via dynamickineticresolution of in situ generated chiral cyanohydrins has been developed. This method involves a reversible cyanohydrin formation/hemiacetalization/intramolecular oxy-Michael addition reactioncascade, affording a chiral syn-1,3-diol structure with simultaneous construction of two stereogenic centers. The use of trifluoromethyl ketones is crucial
Investigations towards the stereoselective organocatalyzed Michael addition of dimethyl malonate to a racemic nitroalkene: possible route to the 4-methylpregabalin core structure
作者:Denisa Vargová、Rastislav Baran、Radovan Šebesta
DOI:10.3762/bjoc.14.42
日期:——
obtained by organocatalyticMichaeladditions. We show here the stereoselective synthesis of 4-methylpregabalin stereoisomers using a Michaeladdition of dimethyl malonate to a racemic nitroalkene. The key step of the synthesis operates as a kinetic resolution with a chiral squaramide catalyst. Furthermore, specific organocatalysts can provide respective stereoisomers of the keyMichael adduct in up