Indole Alkaloids from Vinca erecta, Structure and Stereochemistry

Crystal Structure of the Norfluorocurarine Quaternization Products

“…The indole core is almost planar, but the ring B is distorted toward the 2α-envelope and twist conformations, the six-membered rings C and D adopt the twist-boat conformation, the five-membered ring Е has the 5α-envelope shape (Scheme 1). The conformations coincide with those in retains the Z shape typical of V. erecta indole alkaloids [12]. The bond lengths and bond angles in all structural fragments, including the indole ring, the polycyclic framework, the exomethylene moiety, and the aromatic core, have normal values [13].…”

Formation of anti‐Bredt‐type azabicyclo[4.2.0]octene frameworks through photochemical intramolecular [2+2] cycloaddition between indole and a distal double bond of allene

“…HRMS (ESI + ) m/z 266.0949 (M+Na + ), calcd for C 15 H 14 FNNaO: 266.0952. 1 H NMR (400 MHz, CDCl 3 ) δ 8.57 (d, J = 1.9 Hz, 1H), 7.86 (d, J = 3.9 Hz, 1H), 7.44 (d, J = 8.3 Hz, 1H), 7.24 (dd, J = 8.3, 1.9 Hz, 1H), 6.54 (dd, J = 3.9, 0.6 Hz, 1H), 5.54 (t, J = 6.7 Hz, 1H), 4.97 (d, J = 6.7 Hz, 2H), 1.55 (s, 6H). 13…”

“…Indoline-fused ring systems are common structural motifs in a number of indole alkaloids, which form an important class of biologically active compounds, such as pharmaceuticals, agrochemical, and so on [1][2][3]. In addition to known natural compounds, unprecedented fused cyclic indoline frameworks are of interest in bioactive screening for new pharmaceutical candidates [4][5][6][7].…”

“…IR (KBr) 2980, 2958, 1686, 1598, 1471, 1458, 1331, 1277, 1155, 1099, 835, 772, 760 cm À1 . 1 H NMR (400 MHz, CDCl 3 ) δ 7.71 (d, J = 7.9 Hz, 1H), 7.24-7.20 (m, 2H), 7.04 (dt, J d = 1.1, J t = 7.4 Hz, 1H), 5.56-5.54 (m, 1H), 5.24 (dt, J d = 9.0, J t = 2.3 Hz, 1H), 3.93 (dt, J d = 3.5, J t = 9.0 Hz, 1H), 3.45 (ddd, J = 15.3, 9.0, 2.4 Hz, 1H), 2.87-2.81 (m, 1H), 1.46 (s, 3H), 1.32 (s, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ 182.…”

“…UV-vis (1.7 Â 10 À4 mol/L, ethyl acetate) λ max 302 nm (ε 6.5 Â 10 3 ). IR (KBr) 3170,2981, 1955, 1696, 1538, 1448, 1390, 1308, 1207, 1154, 1077, 901, 852, 757, 719 cm À1 1. H NMR (400 MHz, CDCl 3 ) δ 8.51 (d, J = 8.3 Hz, 1H), 7.88 (d, J = 3.9 Hz, 1H), 7.54 (d, J = 7.7 Hz, 1H), 7.37-7.33 (m, 1H), 7.29-7.25 (m, 1H), 6.57 (d, J = 3.9 Hz, 1H), 5.56 (t, J = 6.8 Hz, 1H), 4.97 (d, J = 6.8 Hz, 2H), 1.56 (s, 6H).13 C NMR (100 MHz, CDCl 3 ) δ 206.5 (C), 174.6 (C), 136.5 (C), 129.6 (C), 126.3 (CH), 125.1 (CH), 123.7 (CH), 120.5 (CH), 117.2 (CH), 108.2 (CH), 97.7 (CH), 79.1 (CH 2 ), 44.6 (C), 27.2 (CH 3 ).…”