An efficient preparation of macrocycles 7 and 9 bearing vinamidine moieties is described. The key to the preparation is the (2:2) cyclocondensation of malonaldehyde derivatives 1 and 8 and 1,Ï-diaminoalkanes 6.
作者:Tietze, Lutz F.、Bergmann, Andreas、Brill, Gunter、Brueggemann, Klaus、Hartfiel, Uwe、Voss, Edgar
DOI:——
日期:——
Stereoselective sequential photochemical cycloaddition - iminium ion - propargylsilane cyclization. Synthesis of quinolizidines and pyrido [1,2-a]azepines
作者:Lutz F. Tietze、Josef R. Wünsch、Mathias Noltemeyer
DOI:10.1016/s0040-4020(01)88876-1
日期:1992.1
Photochemical cycloaddition of the enaminecarbaldehydes 15 and 16 with the acrylic acid derivatives 20a-c gave the 2-hydroxytetrahydropyridines 21a-c and 24a-c, respectively which cyclize on treatment with trifluoroacetic acid or Lewis acids to furnish the quinolizidines 22a-c and pyrido[1,2-a]azepines 25a-c, respectively in good yields and with high 1,3-induced diastereoselectivity. Indolizidines 27 cannot be prepared by this method.
METHYL DIFORMYLACETATE
作者:Hutchinson、Nakane、Gollman、Knutson
DOI:10.15227/orgsyn.064.0144
日期:——
Chirality transfer in the ene-reactions of 3-{2-(2S)-[2-(substituted)vinyl]pyrrolidin-1-yl}-2-(substituted)acrolein derivatives
Ene-reactions of 3-2-(2S)-[2-(substituted)vinyl]pyrrolidin-1-yl}-2-(substituted)acrolein derivatives 5, 8, 13, and 16 have been described. Carbonyl-ene reaction of 5 and 16 and imine-ene reaction of 8 proceeded in a highly selective manner to lead to azepine derivatives 6 and 17, and 9, respectively. The chirality of the starting acroleins was transferred almost perfectly to the azepine-ring through