作者:Inge Bock、Hans Bornowski、Andreas Ranft、Heinz Theis
DOI:10.1016/s0040-4020(01)86685-0
日期:1990.1
3-substituted furan systems can be obtained by alkylation of 3-lithium furans with various electrophiles in the presence of hexamethylphosphoric acid triamide in good yields. The 2- or 5-position of 3-methyl furan is blocked with high regioselectivity by silylation. After metalation and alkylation of the remaining free α-position and subsequent desilylation the 2,3- and 2,4-disubstituted furans are
在六甲基磷酸三酰胺存在下,通过将3-锂呋喃与各种亲电试剂进行烷基化反应,可以得到3-取代的呋喃系统。3-甲基呋喃的2-或5-位被甲硅烷基化以高区域选择性封闭。在将剩余的游离α-位置金属化和烷基化并随后进行甲硅烷基化之后,得到2,3-和2,4-二取代的呋喃。这些方法用于合成天然存在的化合物乌索尔醇化物()和longifolin()。