Elsamicins A and B, new antitumor antibiotics related to chartreusin. 2. Structures of elsamicins A and B

A Unified Strategy for the Asymmetric Synthesis of Highly Substituted 1,2-Amino Alcohols Leading to Highly Substituted Bisoxazoline Ligands

“…Integration is provided, and assignments are indicated. 1 H and 13 C assignments are corroborated through 2-D NMR experiments (COSY, HSQC, HMBC).…”

“…1 H and 13 C[ 1 H] NMR spectra were recorded Bruker 500 (500 MHz, 1 H; 126 MHz, 13 C) MHz spectrometers. Acquisition times were 4.096 s for 1 H NMR and 1.024 s for 13 C NMR. Spectra are referenced to residual chloroform (δ = 7.26 ppm, 1 H; 77.16 ppm, 13 C).…”

“…The crude product was purified by column chromatography (silica, 3 cm ⌀ × 15 cm column) eluting with hexanes/EtOAc, 7:3 gradient to 0:1 to afford 34 (1.40 g, 81%) as a white solid. Data for 34: mp 214−216 °C (hexanes/EtOAc); 1 H NMR (500 MHz, CDCl 3 ) δ 7.78 (d, J = 8.6 Hz, 2H, HN(4)), 7.61 (d, J = 7.7 Hz, 4H, HC( 9)), 7.39−7.33 (m, 8H, HC(10,17)), 7.32−7.25 (m, 12H, HC(9′,10′,18)), 7.25−7.17 (m, 8H, HC(14,11′,19)), 7.17−7.12 (m, 2H, HC( 11)), 6.94 (d, J = 8.2 Hz, 4H, HC( 13)), 6.10 (d, J = 8.6 Hz, 2H, HC(5)), 2.67 (s, 2H, HO( 7)), 0.97 (s, 6H, HC(1)); 13 (35). A 50 mL, one-necked Schlenk flask containing an egg-shaped stir bar (15.9 × 6.35 mm) was charged with 23 (1.76 g, 4.4 mmol, 2.0 equiv), Et 3 N (1.11 g, 1.53 mL, 11.0 mmol, 5.0 equiv), and CH 2 Cl 2 (10 mL) under nitrogen.…”

“…Bioactive lipids such as sphingosine and myriocin also contain a 1,2-amino alcohol moiety. 1,2-Amino alcohols are found as aminoglycosides in various natural products such as daunomycin, elsamicin A, and neomycin B . In addition to these natural products, synthetic, pharmacologically active molecules like saquinavir possess these moieties .…”

Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products

“…chartreusin (461, formerly named X-465A), have been isolated from S. chartreusis (1092)(1093)(1094)(1095)(1096)(1097)(1098), and the elsamicins A (462) and B (463) have been found in the actinomycete strain 1907-21 (1099,1100). chartreusin (461, formerly named X-465A), have been isolated from S. chartreusis (1092)(1093)(1094)(1095)(1096)(1097)(1098), and the elsamicins A (462) and B (463) have been found in the actinomycete strain 1907-21 (1099,1100).…”