Chlorodicyclohexylborane-Mediated Aldol Additions of α,α‘-Dioxygenated Ketones
作者:Juan Murga、Eva Falomir、Miguel Carda、Florenci González、J. Alberto Marco
DOI:10.1021/ol015542f
日期:2001.3.1
stereoselectivity of the process was dependent on the protecting group on the alpha-oxygen atoms. Notably, ketones with bulky silyloxy groups gave syn aldols, most likely via Z enolates. This rules out the participation of chelates during the enolization process, at least in the presence of such sterically crowded protecting groups. An alternative explanation is offered.
DIASTEREOSELECTION IN A DIRECTED CROSSED ALDOL REACTION BETWEEN TWO POLYOXYGENATED KETONES EMPLOYING TIN(II) ENOLATES. A FACILE STEREOSELECTIVE SYNTHESIS OF ETHYL 2-<i>C</i>-METHYL-DL-LYXOFURANOSIDE
作者:Rodney W. Stevens、Teruaki Mukaiyama
DOI:10.1246/cl.1983.595
日期:1983.4.5
Tin(II) enolates of 1,3-dihydroxy-2-propanone derivatives react with a second ketone, methyl pyruvate, under mild conditions to afford the corresponding anti-crossed aldol products in moderate to excellent yields. Facile elaboration to the branched-chainsugar, ethyl 2-C-methyl-DL-lyxofuranoside, was demonstrated.
1,3-二羟基-2-丙酮衍生物的锡 (II) 烯醇化物与第二种酮丙酮酸甲酯在温和条件下反应,以中等至极好的产率提供相应的抗交叉羟醛产物。证明了对支链糖乙基 2-C-甲基-DL-lyxofuranoside 的简单加工。