Synthesis of eleven-membered carbocycles via a homo-Cope type of five-carbon ring expansion reaction utilized β-(hydroxymethyl)allylsilane
作者:Hideyuki Suzuki、Chiaki Kuroda
DOI:10.1016/s0040-4020(03)00348-x
日期:2003.4
ratio. The (Z)-substrate with respect to allylsilane moiety afforded the same ringexpansion product, however, the yield was lower than the reaction with the (E)-substrate. The substrates bearing t-butyl or benzyloxy substituents on the cyclohexane ring also afforded the product analogously, indicating that the reaction depends upon the conformation of the substrate. On the other hand, the substrate
Organocatalyzed Tsuji–Trost reaction: a new method for the closure of five- and six-membered rings
作者:Bojan Vulovic、Filip Bihelovic、Radomir Matovic、Radomir N. Saicic
DOI:10.1016/j.tet.2009.10.006
日期:2009.12
A combination of organotransition metal catalysis and organocatalysis allows for Tsuji–Trost 5-exo- and 6-exo-cyclizations of aldehydes. This transformation can also be accomplished as a catalytic asymmetric reaction, which affords vinylcyclopentane derivatives with up to 98%ee.
Asymmetric synthesis of 1,2-disubstituted cycloalkanecarboxaldehydes. procedures for the highly stereoselective preparation of cis- and trans-isomer
作者:Hiroshi Kogen、Kiyoshi Tomioka、Shun-ichi Hashimoto、Kenji Koga
DOI:10.1016/s0040-4039(00)92856-9
日期:1980.1
Procedures for the asymmetric synthesis of 1,2-disubstituted cycloalkanecarboxaldehydes () having assymetric tertiary and quaternary carbon atoms in vicinal positions from the corresponding cycloalkenecarboxaldehydes () in high diastereomeric and enantiomeric purities are described.
Diastereoselective and enantioselective synthesis of 1,2-disubstituted cycloalkanecarboxaldehydes
作者:Hiroshi Kogen、Kiyoshi Tomioka、Shun-Ichi Hashimoto、Kenji Koga
DOI:10.1016/s0040-4020(01)93269-7
日期:——
quaternary carbon atoms in vicinal positions in their rings, is devised starting from cycloalkenecarboxal-dehydes (5) t-Leucine t-butyl ester (2, R=But), a highly effective chiral auxiliary reagent in the present method, can be recovered for recycling without any loss of optical purity Some mechanistic explanations on the stereochemicalcourses of the reactions are presented
对于非对映选择性和对映选择性合成一个非常有用的方法反式-和顺-1,2-二取代cycloalkanecarboxaldehydes(反式-和顺式- 10),有用的手性合成子具有非对称叔和在其环的邻位位置上的季碳原子,被设计出发可以从本方法中的高效手性助剂-环烯烃羧醛(5)叔亮氨酸叔丁酯(2,R = Bu t)中回收而无需光学纯度损失。介绍了反应的立体化学过程