Ramachandran P Veeraraghavan, Rudd Michael T, Burghardt Thomas E, Ram Reddy M Venkat
Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, Indiana 47907-2084, USA.
J Org Chem. 2003 Nov 28;68(24):9310-6. doi: 10.1021/jo034954u.
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.
开发了一种用于制备[α-(乙氧羰基)乙烯基]二异丁基铝及其β-甲基或β-苯基类似物的改进的氢化铝化方法。这些乙烯基铝试剂与醛和酮反应，以良好至优异的产率提供相应的官能化烯丙醇。全氟烷基和芳基羰基化合物、α-酮酯、α-酰基氰化物和α-炔酮以高产率提供相应的α-羟基烯烃。用[α-(乙氧羰基)乙烯基]二异丁基铝及其β-甲基或β-苯基类似物对不对称α-二酮进行乙烯基铝化反应得到的烯丙醇产物比例取决于酮以及试剂的空间和电子环境。α-溴代醛和酮的乙烯基铝化产物在非水条件下用碳酸钾或氟化钾环化，以高产率提供官能化的环氧乙烯。酮保护的丙酮酸的乙烯基铝化反应得到产物，该产物被转化为α-亚烷基-β-羟基-γ-内酯。
