HIGHLY REGIOSELECTIVE GENERATION OF "THERMODYNAMIC" ENOLATES AND THEIR DIRECT CHARACTERIZATION BY NMR

Article abstract of DOI:10.1016/S0040-4039(00)81651-2

Addition of 2-methylcyclohexanone to 1.05 equiv of KH suspended in THF, followed by treatment with 1.25 equiv of BEt3 gives potassium enoxyborate 2a as a 90-95percent regioisomerically pure species, as judged by its 1H and 13C NMR as well as by GLC analysis of the silylated products, while the use of KN(SiMe3)2 in place of KH gives 1a as a 90-95percent pure substance.The KH-BEt3 procedure also gives 4 and 5 as 91 and 85percent regiochemically pure species, respectively.