Total Synthesis of Ustiloxin D

Copper-Catalyzed Modular Assembly of Polyheterocycles

“…Increasing the amount of 6a to 2.0 equiv afforded 7aa in 68% yield (entry 4). However, replacing the catalyst with CuI, CuSO 4 , CuCl, CuBr, CuBr 12). The yield of 7aa decreased to 62% at a temperature of 80 °C (entry 13).…”

“…1 H NMR (500 MHz, DMSO-d 6 ) δ 8.12 (s, 1H), 7.87 (d, J = 8.8 Hz, 1H), 7.63 (d, J = 2.2 Hz, 1H), 7.55−7.47 (m, 2H), 7.42 (dt, J = 7.3, 3.4 Hz, 2H), 6.73 (dd, J = 8.7, 2.3 Hz, 1H), 6.33 (s, 2H), 5.11 (s, 2H), 1.28 (s, 9H). 13 (12). It was synthesized according to procedure G on a 0.1 mmol scale (32 mg, 64%) as a red solid; mp: 277−278 °C; R f = 0.36 (70% EtOAc/petroleum ether).…”

“…10 Hutton et al synthesized ustiloxin D utilizing an ammonia− Ugi reaction (Figure 1C). 12 Recently, Polindara-Garci ́a and his colleagues developed a novel protocol for the fast introduction of the picolinamide directing group in aliphatic ketones using the ammonia−Ugi 4-CR reaction and the subsequent Pdmediated γ-C(sp 3 )−H bond activation (Figure 1D). 13 Ullmann−Hurtley condensations are powerful tools for the formation of carbon−heteroatom and carbon−carbon bonds in the construction of a wide variety of heterocycles.…”

Total Synthesis of Seongsanamide B

“…Attempted macrolactonization of 11 under a variety of coupling conditions was unsuccessful. Related macrolactamizations to generate isodityrosine-containing cyclic peptides have proven difficult, 5,6 as have macrolactonizations to generate cyclic depsipeptides. 35−38 Next, we envisaged that cyclization to generate the lactone may be facilitated if the alcohol and acid groups were already constrained in a macrolactam, and thus, a late-stage macrolactonization strategy was pursued.…”