Enantioselective Alkylation of 2,2-Dimethyl-1,3-dioxan-5-one Using the SAMP-/RAMP-Hydrazone Method
作者:Dieter Enders、Bernhard Bockstiegel
DOI:10.1055/s-1989-27298
日期:——
The lithiated SAMP-hydrazone (S)-3 [(S)-1-(2,2-dimethyl-1, 3-dioxan-5-ylideneamino)-2-methoxymethylpyrrolidine] is used as a chiral 1,3-dihydroxyacetone-enolate equivalent C in overall enantioselective α-alkylations leading to 4-alkyl-2,2-dimethyl-1,3-dioxan-5-ones (S)-5a-i in good overall chemical yields and of high enantiomeric purity (ee = 88 - ⧠93%.
石化的 SAMP-腙 (S)-3 [(S)-1-(2,2-二甲基-1,3-二氧杂环戊烷-5-亚基氨基)-2-甲氧基甲基吡咯烷] 被用作手性 1、在整体对映选择性δ-±-烷基化反应中作为手性 1,3-二羟基丙酮-烯酸酯等效物 C,可得到 4-烷基-2,2-二甲基-1,3-二氧杂环戊-5-酮 (S)-5a-i,整体化学收率高,对映体纯度高(ee = 88 - â§ 93%)。