Reaction Steps
compound A416. Same procedure as above with Trp-NHCH2Ph (63.03 mg, 0.215 mmol), N-Boc-Tyr(Bn)-Asn-OH (105.0 mg, 0.216 mmol), EDC (44 mg, 0.226 mmol) and HOBt (31 mg, 0.226 mmol) in CH2Cl2/DMF (1.5 mL/1.5 mL). After treatment, the crude residue was triturated with CH2Cl2/pentane to afford a white solid (78 mg, 48%). 1H NMR (300 MHz, DMSO-d6) δ 1H NMR (300 MHz, DMSO-d6) δ 1.29 (s, 9H, (CH3)3), 2.30-3.26 (m, 6H, CH2 Tyr, CH2 Trp, CH2 Asn), 4.08 (m, 1H, CHα), 4.24 (s, 2H, NCH2Ph), 4.49 (m, 1H, CHα), 4.56 (m, 1H, CHα), 5.03 (broad s, 2H, OCH2Ph), 6.88-7.56 (m, 17H), 8.17 (d, J=8 Hz, 1H, NH), 8.23 (d, J=8 Hz, 1H, NH), 8.51 (t, J=6 Hz, 1H, NH), 10.84 (s, 1H, NH). 13C NMR (75 MHz, CD3OD) δ 28.5 (CH2 Trp), 28.6 ((CH3)3), 37.3, 38.1 (CH2 Tyr, CH2 Asn), 44.1 (NCH2Ph), 51.7, 55.9, 57.6 (CHα Tyr, Asn, Trp), 71.0 (OCH2Ph), 80.9 (C Boc), 110.9 (C), 112.4, 115.9, 116.0, 119.4, 119.9, 122.5, 124.8, 128.0, 128.5, 128.6, 128.8, 129.4, 129.5, 130.6 (C), 131.4 (CH), 138.0, 138.8, 139.5 (aromatic C), 157.9, 159.1 (aromatic C and CO Boc), 172.7, 173.6, 174.4, 174.9 (CO amide).
