Synthesis and structure elucidation of open-chained putrescine-bisamides from Aglaia species

Total synthesis of (+)-grandiamide D, dasyclamide and gigantamide A from a Baylis–Hillman adduct: A unified biomimetic approach

“…Except for the elaborate synthetic work carried out by Hesse and Detterbeck [6], who described the synthesis of nine putrescine bisamides isolated from different Aglaia species along with the structural revision for one of the compounds and determination of absolute configuration for another compound, no other literature precedence is available till now.…”

“…There is only a limited number of putrescine bisamides isolated from natural sources and the amount of synthetic approaches known for these structurally interesting and biologically important molecules is quite low. Except for the elaborate synthetic work carried out by Hesse and Detterbeck [ 6 ], who described the synthesis of nine putrescine bisamides isolated from different Aglaia species along with the structural revision for one of the compounds and determination of absolute configuration for another compound, no other literature precedence is available till now.…”

Biology-Orientated Synthesis of Putrescine Bisamides Gigantamide A, Dasyclamide, and Cucullamide

“…The aqueous layer was saturated with NaCl and then neutralized with aq 20% NaOH (20 mL). The basified mixture was extracted with CH 2 Cl 2 (3 × 25 mL) and the combined extracts were dried (Na 2 SO 4 ) and concentrated in vacuo to give amine 4b 19 as a viscous yellow oil; yield: 2.35 g (86%).…”

“…The combined organic layers were washed with brine (25 mL), dried (Na 2 SO 4 ), and concentrated in vacuo. The residue was purified by column chromatography (silica gel, EtOAc-PE, 1:1) to afford pure amide 3b19 as a white solid; yield: 4.08 g (95%); mp 92-94 °C.IR (CHCl3 ): 3449, 3349, 1700, 1665, 1624 cm -1 . 1 H NMR (200 MHz, CDCl 3 ): δ = 1.45 (s, 9 H), 1.50-1.68 (m, 4 H), 3.16 (q, J = 6 Hz, 2 H), 3.41 (q, J = 6 Hz, 2 H), 4.70 (br s, 1 H), 6.28 (br s, 1 H), 6.45 (d, J = 16 Hz, 1 H), 7.30-7.40 (m, 3 H), 7.43-7.53 (m, 2 H), 7.62 (d, J = 16 Hz, 1 H).…”

Bioactive Sesquiterpene Lactones from Eupatorium Kiirunense

“…The methyl proton signal at δ H 1.87 (brs, H-15) was 3 J-correlated to an oxymethine carbon at δ C 66.4 assigned to C-3 while the proton at δ H 4.95 (H-3) was correlated to another oxymethine carbon at δ C 59.5 that was directly attached to a proton at δ H 2.58 (H-1). HMBC correlations ( Figure 1) between the methyl signal at δ H 1.49 (H- 14) and carbon signals at δ C 59.5(C-1) and δ C 43.3(C-9) together with the presence of a quaternary carbon at δ C 56.9 (C-10) implied the presence of a 1,10-epoxy ring [9,10]. The small value of J 7,13 (1.2 Hz) revealed the Z-geometry of the C-4/C-5 double bond [11][12][13] .…”