Diastereoselective synthesis of γ,γ-disubstituted β-hydroxy α,α-difluoro-γ-butyrolactones
作者:Tatsuro Ishikawa、Satoru Arimitsu
DOI:10.1016/j.jfluchem.2022.110028
日期:2022.9
The L-proline catalyzed synthesis of α,α-difluoro homoallylic aldehydes was modified, and these aldehydes bearing either aromatic or aliphatic groups the γ-position were obtained with excellent E/Z selectivity (E/Z ≥ 20/1) in a practical manner. Thereafter, the obtained aldehydes were readily transformed into α,α-difluoro homoallylic esters in moderate yields (53–74%) over three steps, maintaining
对L-脯氨酸催化合成α,α-二氟均烯丙基醛进行了改性,在实际应用中得到了具有优异E/Z选择性(E/ Z≥20/1)的γ位带有芳香族或脂肪族基团的醛。方式。此后,获得的醛在三个步骤中以中等收率 (53-74%) 容易地转化为 α,α-二氟均烯丙基酯,保持优异的E/Z选择性 ( E/Z≥ 20/1)。这些酯可以与间氯过氧苯甲酸进行环氧化,原位生成 3,4-环氧酯,再用 NaOH 水溶液处理得到 γ,γ-二取代 β-羟基 α,α-二氟-γ-丁内酯以低至中等的分离产率 (20–72%),具有出色的非对映选择性 ( dr ≥ 20/1)。