Reaction SMILES: [CH3:1][C@:2]12[CH2:18][CH2:17][C@H:16]([O:19][CH2:20][CH2:21][CH2:22][NH:23][C:24](=[O:81])[CH2:25][CH2:26][C:27]([NH:29][C@H:30]([CH2:39][C:40]([NH:42][C@@H:43]([CH2:55][CH2:56][CH2:57][CH2:58][N:59]([C:73]3[CH:78]=[CH:77][C:76]([O:79][CH3:80])=[CH:75][CH:74]=3)[CH:60]([C:67]3[CH:72]=[CH:71][CH:70]=[CH:69][CH:68]=3)[C:61]3[CH:66]=[CH:65][CH:64]=[CH:63][CH:62]=3)[C:44]([NH:46][C:47]3[CH:52]=[CH:51][C:50]([CH2:53][OH:54])=[CH:49][CH:48]=3)=[O:45])=[O:41])[CH2:31][C:32]3[CH:37]=[CH:36][C:35]([F:38])=[CH:34][CH:33]=3)=[O:28])[CH2:15][C:14]1=[CH:13][CH2:12][C@@H:11]1[C@@H:3]2[CH2:4][CH2:5][C@@:6]2([CH3:90])[C@H:10]1[CH2:9][CH2:8][C@@H:7]2[C@@H:82]([CH2:84][CH2:85][CH2:86][CH:87]([CH3:89])[CH3:88])[CH3:83].CCN(C(C)C)C(C)C.C(Cl)Cl.[C:103](=O)([O:114]C1C=CC([N+]([O-])=O)=CC=1)[O:104][C:105]1[CH:110]=[CH:109][C:108]([N+:111]([O-:113])=[O:112])=[CH:107][CH:106]=1>CN(C=O)C>[C:103](=[O:114])([O:104][C:105]1[CH:106]=[CH:107][C:108]([N+:111]([O-:113])=[O:112])=[CH:109][CH:110]=1)[O:54][CH2:53][C:50]1[CH:49]=[CH:48][C:47]([NH:46][C:44](=[O:45])[C@@H:43]([NH:42][C:40](=[O:41])[CH2:39][C@@H:30]([NH:29][C:27](=[O:28])[CH2:26][CH2:25][C:24]([NH:23][CH2:22][CH2:21][CH2:20][O:19][C@@H:16]2[CH2:15][C:14]3[C@@:2]([CH3:1])([C@@H:3]4[C@@H:11]([CH2:12][CH:13]=3)[C@H:10]3[C@@:6]([CH3:90])([C@@H:7]([C@@H:82]([CH2:84][CH2:85][CH2:86][CH:87]([CH3:89])[CH3:88])[CH3:83])[CH2:8][CH2:9]3)[CH2:5][CH2:4]4)[CH2:18][CH2:17]2)=[O:81])[CH2:31][C:32]2[CH:37]=[CH:36][C:35]([F:38])=[CH:34][CH:33]=2)[CH2:55][CH2:56][CH2:57][CH2:58][N:59]([C:73]2[CH:74]=[CH:75][C:76]([O:79][CH3:80])=[CH:77][CH:78]=2)[CH:60]([C:67]2[CH:68]=[CH:69][CH:70]=[CH:71][CH:72]=2)[C:61]2[CH:66]=[CH:65][CH:64]=[CH:63][CH:62]=2)=[CH:52][CH:51]=1
Reactant: COc1ccc(N(CCCC[C@H](NC(=O)C[C@H](Cc2ccc(F)cc2)NC(=O)CCC(=O)NCCCO[C@H]2CC[C@@]3(C)C(=CC[C@H]4[C@@H]5CC[C@H]([C@H](C)CCCC(C)C)[C@@]5(C)CC[C@@H]43)C2)C(=O)Nc2ccc(CO)cc2)C(c2ccccc2)c2ccccc2)cc1
Reactant: O=C(Oc1ccc([N+](=O)[O-])cc1)Oc1ccc([N+](=O)[O-])cc1
Solvent: ClCCl
Solvent: CN(C)C=O
Solvent: CCN(C(C)C)C(C)C
Product: COc1ccc(N(CCCC[C@H](NC(=O)C[C@H](Cc2ccc(F)cc2)NC(=O)CCC(=O)NCCCO[C@H]2CC[C@@]3(C)C(=CC[C@H]4[C@@H]5CC[C@H]([C@H](C)CCCC(C)C)[C@@]5(C)CC[C@@H]43)C2)C(=O)Nc2ccc(COC(=O)Oc3ccc([N+](=O)[O-])cc3)cc2)C(c2ccccc2)c2ccccc2)cc1
Yield: 55.2 %

Procedure:
In a 10 mL round-bottomed flask, the above prepared N1-(3-((3S,8S,9S,10R,13R,14S,17R)-10,13-dimethyl-17-((R)-6-methylheptan-2-yl)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yloxy)propyl)-N4-((S)-1-(4-fluorophenyl)-4-((S)-1-(4-(hydroxymethyl)phenylamino)-6-((4-methoxyphenyl)diphenylmethylamino)-1-oxohexan-2-ylamino)-4-oxobutan-2-yl)succinamide (196 mg, 160 μmol, Eq: 1.00) and Huenig's base (61.9 mg, 81.4 μl, 479 μmol, Eq: 3.00) were combined with CH2Cl2 (1.6 ml) and DMF (0.8 ml) to give a yellow suspension; bis(4-nitrophenyl) carbonate (72.8 mg, 239 μmol, Eq: 1.50) was added and the reaction allowed to proceed at ambient temperature over night. The mixture was poured onto crashed ice/NH4Cl (pH ˜6), extracted 2× with AcOEt, washed with H2O and brine, dried over Na2SO4, and evaporated to dryness. After trituration with AcOEt/heptane one obtained 123 mg of the title compound as light yellow solid. MS: expected mass: 1392.7825, found mass: 1392.7819.