An efficient method for α-monofluorination of carbonyl compounds with molecular fluorine: Use of α-hydroxymethylene substituent as directing and activating groups
作者:Hiroshi Kamaya、Masayuki Sato、Chikara Kaneko
DOI:10.1016/s0040-4039(96)02378-7
日期:1997.1
Molecular fluorine efficiently reacts with α-hydroxymethylene carbonyl compounds to give α-fluoro-α-formyl compounds in a highly site-specific manner. The fluorinated compounds mostly isolated as their hemiacetals with methanol are readily deformylated just by treatment with weak bases affording α-monofluorinated carbonyl compounds. In this fluorination method, the hydroxymethylene group serves not
分子氟与α-羟基亚甲基羰基化合物有效反应,以高度位点特异性的方式得到α-氟-α-甲酰基化合物。仅通过用甲醇提供α-单氟化羰基化合物的弱碱处理,就可以容易地将大部分以半缩醛形式与甲醇分离的氟化化合物变形。在该氟化方法中,羟甲基不仅用作氟的羰基化合物的导向基团,而且用作活化基团。通过这种方法,以高收率合成了包括酯在内的一系列α-氟代羰基化合物。