Stereoselective and Competitive [1,2]‐ and [2,3]‐Wittig Rearrangements of Allyl Heteroarylalkyl Ethers
作者:Vito Capriati、Saverio Florio、Giovanni Ingrosso、Catia Granito、Luigino Troisi
DOI:10.1002/1099-0690(20022)2002:3<478::aid-ejoc478>3.0.co;2-#
日期:2002.2
allyl heteroarylalkylic alcohols were obtained as products of stereoselective [2,3]- or [1,2]-Wittig rearrangements, respectively. Homoallylic alcohols were obtained in high yields and with fairly good enantiomeric enrichments when the reactions were carried out in toluene with (−)-sparteine as the external chiral ligand.
已经合成了几种烯丙基杂芳基烷基醚,然后在-78℃下用正丁基锂在THF中脱质子化,得到锂衍生物。取决于相关的质子酸度,含锂末端为α-或α'-碳原子。在没有外部亲电试剂的情况下,发生σ重排,产生新的CC键。杂芳基烷基均烯丙基醇和烯丙基杂芳基烷基醇分别作为立体选择性[2,3]-或[1,2] -Wittig重排的产物获得。当在甲苯中以(-)-天冬氨酸作为外部手性配体进行反应时,以高收率和相当良好的对映异构体富集得到均烯丙基醇。