title: Vinylalumination for the synthesis of functionalized allyl alcohols, vinylepoxides, and alpha-alkylidene-beta-hydroxy-gamma-lactones.
abstract: A modified hydroalumination protocol for the preparation of [alpha-(ethoxycarbonyl)vinyl]diisobutylaluminum and its beta-methyl or -phenyl analogues was developed. These vinylaluminum reagents react with aldehydes and ketones to provide the corresponding functionalized allyl alcohols in good to excellent yields. Perfluoroalkyl and -aryl carbonyl compounds, alpha-keto esters, alpha-acyl cyanides, and alpha-acetylenic ketones provide the corresponding alpha-hydroxyalkenes in high yields. The allyl alcohol product ratios from the vinylalumination of unsymmetrical alpha-diketones with [alpha-(ethoxycarbonyl)vinyl]diisobutylaluminum and its beta-methyl or -phenyl analogues depend on the steric and electronic environments of the ketones as well as the reagents. The products from the vinylalumination of alpha-bromoaldehydes and -ketones were cyclized with K2CO3 or KF under nonaqueous conditions to provide functionalized vinylepoxides in high yields. Vinylaluminations of keto-protected pyruvaldehyde provided the products, which were converted to alpha-alkylidene-beta-hydroxy-gamma-lactones.
authors: Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, Indiana 47907-2084, USA.
authors: P Veeraraghavan
authors: PV
authors: Ramachandran
authors: Michael T
authors: MT
authors: Rudd
authors: Thomas E
authors: TE
authors: Burghardt
authors: M Venkat
authors: MV
authors: Ram Reddy