Traceless Stereoinduction for the Enantiopure Synthesis of Substituted-2-Cyclopentenones

The pseudoenantiomeric 4-O-Boc- and 4-OPMP-cyclopent-2-enones, readily available from hydroxy­methylene­furane on multigram scale, are demonstrated to be exceptional building blocks for the synthesis of enantiopure 4-alkyl-5-(1′-hydroxyalkyl) substituted 2-cyclo­pentenones and derivatives thereof. The 4-OR substituent acts as a traceless stereoinducing element, conferring not only 1,2- but also 1,4-stereocontrol with excellent selectivity. The methodology developed here was applied for the rapid synthesis of natural products and biologically active 2-cyclo­pentenones such as TEI-9826, guaianes, and pseudoguaianolides