Enantioenriched Dihydropyrones from β-Lactone Templates
作者:G. Greg Zipp、Mark A. Hilfiker、Scott G. Nelson
DOI:10.1021/ol025607u
日期:2002.5.1
[reaction: see text] Optically active 4-substituted 2-oxetanones provide conduits for preparing 2,3-dihydro-4H-pyrone heterocycles. Enantioenriched beta-lactones are prepared by asymmetriccatalyticacylhalide-aldehydecyclocondensationreactions. Hydrazone anion-mediated beta-lactone ring opening and ensuing cyclization-dehydroamination of the derived beta-ketohydrazone afford the desired dihydropyrones
Formal Synthesis of Leustroducsin B via Reformatsky/Claisen Condensation of Silyl Glyoxylates
作者:Stephen N. Greszler、Justin T. Malinowski、Jeffrey S. Johnson
DOI:10.1021/ol2011192
日期:2011.6.17
A formal synthesis of leustroducsin B has been completed. The synthesis relies upon a recently developed Reformatsky/Claisen condensation of silyl glyoxylates and enantioenriched beta-lactones that establishes two of the molecule's three core stereocenters and permits further elaboration to an intermediate in Imanishl's synthesis via reliable chemistry (Prasad reduction, asymmetric pentenylation, Mitsunobu inversion).