Divergent Synthesis of α,γ-Disubstituted γ-Butyrolactones through Diastereoselective Bromolactonization with Alkali Metal Bromide: Asymmetric Total Synthesis of (+)-Dubiusamine C
作者:Katsuhiko Moriyama、Toru Sugiue、Chihiro Nishinohara、Hideo Togo
DOI:10.1021/acs.joc.5b01497
日期:2015.9.18
diastereoselective bromolactonization of α-substituted 4-pentenoic acids and 4-pentenamides via umpolung of bromide by use of alkali metal bromide and Oxone (potassium peroxymonosulfate mixture, 2KHSO5·KHSO4·K2SO4) to obtain mainly cis-products from α-substituted 4-pentenoic acids and trans-products from α-substituted 4-pentenamides, and it was found that the bromonium species generated from KBr and Oxone had higher
已开发出发散的α-取代的溴甲基γ-内酯合成方法,该方法涉及通过使用碱金属溴化物和Oxone(过氧化一硫酸钾混合物2KHSO 5 ·KHSO 4 ·K 2 SO 4)主要由α-取代的4-戊烯酸获得顺式产物,由α-取代的4-戊烯酰胺获得反式产物,发现由KBr和Oxone生成的溴物种具有更高的活性比N-溴代琥珀酰亚胺大。此外,从中分离出作为次要非对映异构体的(+)-二丁胺C的不对称全合成。露兜树(Pandanus dubius)是通过(S)-α-甲基-4-戊烯酸的顺式-选择性溴化内酯法在9个线性步骤中首次完成的,总收率为36%。