A Cyclization Approach toward Five-Membered Heteroaromatico-QuinodimethanesviaFused-3-Sulfolenes
摘要:
AbstractA general strategy involving the zincation of 4‐bromo‐3‐chloro‐2‐sulfolene, in situ condensation with an α‐heterosubstituted acetaldehyde, and subsequent cyclization reaction as the key steps toward the synthesis of furano‐ and thieno‐3‐sulfolenes is described. These fused‐3‐sulfolenes are demonstrated to be good precursors for the corresponding o‐quinodimethanes.
Enzymatic and Organocatalyzed Asymmetric Aldolization Reactions for the Synthesis of Thiosugar Scaffolds
作者:Johan Fanton、Flora Camps、José A. Castillo、Christine Guérard-Hélaine、Marielle Lemaire、Franck Charmantray、Laurence Hecquet
DOI:10.1002/ejoc.201101137
日期:2012.1
We studied the synthesis of original thiosugar scaffolds by enantioselective aldolization. L-Proline-catalyzed C-C bond formation was the key step in the synthesis of L-erythro-thioketoses (3S,4R), whereas fructose-6-phosphate aldolase-catalyzed reactions yielded the D-threo-thioketose series (3S,4S). By the organocatalytic approach, 5-thio-L-ribulofuranose (1) and 5-deoxy-6-thio-L-psicopyranose (2)