Investigation of the asymmetric ionic Diels–Alder reaction for the synthesis of cis-decalins
作者:James C. Anderson、Alexander J. Blake、Jonathan P. Graham、Claire Wilson
DOI:10.1039/b305116a
日期:——
limited subset of cis-decalin structures. Diastereoselectivities of 73% and 82% have been found for the asymmetric ionic Diels-Alder reaction between the chiral acetal derivatives of cyclohex-2-enone (6) and 2-methylcyclohex-2-enone (18) with 2,3-dimethyl-1,3-butadiene (7). Terminal substituents on the diene partner in general render the system unreactive. However a synthetically useful cis-decalin 31
已经开发出离子Diels-Alder反应,其中α,β-不饱和缩醛与路易斯酸或布朗斯台德酸组合形成平衡浓度的活化的亲二烯体,以提供顺式十氢化萘的对映选择性合成。(2R,3R)-丁烷-2,3-二醇的Cyclohex-2-enone型手性缩醛已针对具有各种二烯的Lewis和Brønsted酸进行了筛选,可有效合成有限的顺式十氢萘结构子集。对于环己-2-烯酮(6)和2-甲基环己-2-烯酮(18)的手性乙缩醛衍生物与2,3-二甲基-丁烯之间的不对称离子Diels-Alder反应,发现非对映选择性为73%和82%。 1,3-丁二烯(7)。二烯配偶体上的末端取代基通常使体系不反应。但是,合成上有用的顺式十氢萘31