1.
J Org Chem
; 67(16): 5611-5, 2002 Aug 09.
Artigo
em Inglês
| MEDLINE
| ID: mdl-12153258
RESUMO
The lithium enolates of trimethylsilyl but-3-enoate and 3-methylbut-3-enoate reacted with aldehydes and saturated or aromatic ketones at -70 degrees C to give exclusively the alpha-condensation products in excellent yields. The unsaturated beta-hydroxy acids thus obtained were directly identified, and the usual conversion into their methyl esters with diazomethane was not necessary. Unsaturated ketones underwent Michael reaction through alpha-addition leading to the unsaturated 5-oxo acids.