Custom synthesis of substituted butenolides, dihydropyranones, and α-E-alkylidenelactones via alkenylalumination

Autor: Garrett Garner, P. Veeraraghavan Ramachandran, Debarshi Pratihar, B. China Raju
Rok vydání: 2011
Předmět:
Zdroj: Tetrahedron Letters. 52:4985-4988
ISSN: 0040-4039
Popis: Alkenylalumination of aldehydes with [α-(ethoxycarbonyl)-β-(t-butyldimethylsilyloxyalkyl)alkenyl]diisobutylaluminum provides the corresponding α-Z-alkylidene-β′-hydroxy esters, which upon protection and treatment with trifluoroacetic acid lactonizes to furnish α-acetoxyalkyl butenolides (n = 1) and dihydropyranones (n = 2) in 40% overall yield. Conjugate addition to these lactenones and concurrent acetate elimination constitute a general and stereospecific synthesis of the corresponding α-E-alkylidene lactones.
Databáze: OpenAIRE