(R)- and (S)-3-Hydroxy-4,4-dimethyl-1-phenyl-2-pyrrolidinone as chiral auxiliaries in Diels–Alder reactions
作者:Pelayo Camps、Mercè Font-Bardia、Sı́lvia Giménez、Francesc Pérez、Xavier Solans、Núria Soldevilla
DOI:10.1016/s0957-4166(99)00267-0
日期:1999.8
the chiral auxiliaries (R)- and/or (S)-3-hydroxy-4,4-dimethyl-1-phenyl-2-pyrrolidinone (4, 17, 25 and 26, respectively) with different dienes [cyclopentadiene 5, isoprene 8, 11,12-dimethylene-9,10-dihydro-9,10-ethanoanthracene 9 and anthracene 10], catalyzed by titanium tetrachloride, is described. Cyclopentadiene gave adducts with esters (R)- or (S)-4 and (R)-25 with high endo- and facial-diastereoselectivities
丙烯酸,甲基丙烯酸,反丁烯酸和反肉桂酸酯与手性助剂(R)和/或(S)-3-羟基-4,4-二甲基-的酯的Diels-Alder反应研究1-苯基-2-吡咯烷酮(4,17,25和26,分别地)具有不同的二烯[环戊二烯5,异戊二烯8,11,12-二亚甲基-9,10-二氢-9,10- ethanoanthracene 9和蒽10 ]描述了用四氯化钛催化。环戊二烯与酯(R)-或(S)-形成加合物4和(R)-25具有高的内-和面-非对映选择性。二烯5与(±)-17反应而没有内-非对映选择性,并且未能得到具有(±)-26的环加合物。异戊二烯仅与具有高面部非对映选择性的酯(S)-4反应。9与(R)-4的反应失败,因为二烯在酸性反应条件下不稳定。10和酯(S)-4的加成物(R)-17可以以高的面部非对映选择性获得。由酯(R)-或(S)-4和(R)-25衍生的加合物的LiOH水解得到相应的对映体纯酸,手性助剂被