Reaction SMILES: [C:1]([O:9][C@H:10]1[C@@H:15]([O:16][C:17](=[O:24])[C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C@H:14]([O:25][C:26](=[O:33])[C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)[C@@H:13]([CH2:34][O:35][C:36](=[O:43])[C:37]2[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=2)[O:12][C@@H:11]1[O:44][C@H:45]1[C@H:50]([O:51][C:52](=[O:59])[C:53]2[CH:58]=[CH:57][CH:56]=[CH:55][CH:54]=2)[C@@H:49]([CH2:60][O:61][C:62](=[O:69])[C:63]2[CH:68]=[CH:67][CH:66]=[CH:65][CH:64]=2)[O:48][C@H:47]([O:70][C@H:71]2[C@H:83]([O:84][C:85](=[O:92])[C:86]3[CH:91]=[CH:90][CH:89]=[CH:88][CH:87]=3)[C@@H:82]([CH2:93][O:94][C:95](=[O:102])[C:96]3[CH:101]=[CH:100][CH:99]=[CH:98][CH:97]=3)[O:81][C@H:73]([O:74][CH2:75][CH2:76][CH2:77][N:78]=[N+:79]=[N-:80])[C@H:72]2[O:103][C:104](=[O:111])[C:105]2[CH:110]=[CH:109][CH:108]=[CH:107][CH:106]=2)[C@H:46]1[O:112][C:113](=[O:120])[C:114]1[CH:119]=[CH:118][CH:117]=[CH:116][CH:115]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:121]([O:124][C@H:125]1[CH2:150][CH2:149][C@@:148]2([CH3:151])[CH:127]([CH2:128][CH2:129][C@@H:130]3[C@@H:147]2[CH2:146][CH2:145][C@@:144]2([CH3:152])[C@H:131]3[CH2:132][CH2:133][C@@H:134]2[C@H:135]([CH3:143])[CH2:136][CH2:137][CH2:138][CH:139]([CH3:142])[CH2:140]O)[CH2:126]1)[C:122]#[CH:123].O=C1O[C@H]([C@H](CO)O)C([O-])=C1O.[Na+]>C(Cl)Cl.C(O)(C)(C)C.[O-]S([O-])(=O)=O.[Cu+2]>[C:1]([O:9][C@H:10]1[C@@H:15]([O:16][C:17](=[O:24])[C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C@H:14]([O:25][C:26](=[O:33])[C:27]2[CH:28]=[CH:29][CH:30]=[CH:31][CH:32]=2)[C@@H:13]([CH2:34][O:35][C:36](=[O:43])[C:37]2[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=2)[O:12][C@@H:11]1[O:44][C@H:45]1[C@H:50]([O:51][C:52](=[O:59])[C:53]2[CH:58]=[CH:57][CH:56]=[CH:55][CH:54]=2)[C@@H:49]([CH2:60][O:61][C:62](=[O:69])[C:63]2[CH:68]=[CH:67][CH:66]=[CH:65][CH:64]=2)[O:48][C@H:47]([O:70][C@H:71]2[C@H:83]([O:84][C:85](=[O:92])[C:86]3[CH:87]=[CH:88][CH:89]=[CH:90][CH:91]=3)[C@@H:82]([CH2:93][O:94][C:95](=[O:102])[C:96]3[CH:101]=[CH:100][CH:99]=[CH:98][CH:97]=3)[O:81][C@H:73]([O:74][CH2:75][CH2:76][CH2:77][N:78]3[CH:123]=[C:122]([CH2:121][O:124][C@H:125]4[CH2:150][CH2:149][C@@:148]5([CH3:151])[CH:127]([CH2:128][CH2:129][C@@H:130]6[C@@H:147]5[CH2:146][CH2:145][C@@:144]5([CH3:152])[C@H:131]6[CH2:132][CH2:133][C@@H:134]5[C@H:135]([CH3:143])[CH2:136][CH2:137][CH2:138][CH:139]([CH3:140])[CH3:142])[CH2:126]4)[N:80]=[N:79]3)[C@H:72]2[O:103][C:104](=[O:111])[C:105]2[CH:110]=[CH:109][CH:108]=[CH:107][CH:106]=2)[C@H:46]1[O:112][C:113](=[O:120])[C:114]1[CH:119]=[CH:118][CH:117]=[CH:116][CH:115]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1
Reactant: [N-]=[N+]=NCCCO[C@H]1O[C@H](COC(=O)c2ccccc2)[C@@H](OC(=O)c2ccccc2)[C@H](O[C@H]2O[C@H](COC(=O)c3ccccc3)[C@@H](OC(=O)c3ccccc3)[C@H](O[C@H]3O[C@H](COC(=O)c4ccccc4)[C@@H](OC(=O)c4ccccc4)[C@H](OC(=O)c4ccccc4)[C@@H]3OC(=O)c3ccccc3)[C@@H]2OC(=O)c2ccccc2)[C@@H]1OC(=O)c1ccccc1
Reactant: C#CCO[C@H]1CC[C@@]2(C)C(CC[C@H]3[C@@H]4CC[C@H]([C@H](C)CCCC(C)CO)[C@@]4(C)CC[C@@H]32)C1
Agent: [Cu+2]
Agent: O=C1O[C@H]([C@@H](O)CO)C([O-])=C1O
Agent: O=S(=O)([O-])[O-]
Solvent: ClCCl
Solvent: CC(C)(C)O
Product: CC(C)CCC[C@@H](C)[C@H]1CC[C@H]2[C@@H]3CCC4C[C@@H](OCc5cn(CCCO[C@H]6O[C@H](COC(=O)c7ccccc7)[C@@H](OC(=O)c7ccccc7)[C@H](O[C@H]7O[C@H](COC(=O)c8ccccc8)[C@@H](OC(=O)c8ccccc8)[C@H](O[C@H]8O[C@H](COC(=O)c9ccccc9)[C@@H](OC(=O)c9ccccc9)[C@H](OC(=O)c9ccccc9)[C@@H]8OC(=O)c8ccccc8)[C@@H]7OC(=O)c7ccccc7)[C@@H]6OC(=O)c6ccccc6)nn5)CC[C@]4(C)[C@H]3CC[C@]12C
Temperature: 25 °C
Reaction time: 72 h
Yield: 36.2 %

Procedure:
To a mixture of 57 (81 mg, 0.0497 mol), 3β-(prop-2-ynyloxy)cholestanol (43 mg, 0.0994 mmol, 2 eq) in DCM (64 μL) and t-butanol (60 μL) (0.4 M) was added a solution of CuSO4 (0.3 M in water, 33 μL, 0.00994 mmol, 0.2 eq) and a solution of sodium ascorbate (1M in water, 20 μL, 0.0199 mmol, 0.4 eq). The mixture was vigorously stirred at r.t. for 3 days. The mixture was evaporated onto silica gel and purified by silica column chromatography (2×14 cm, gradient elution with hexane-EtOAc 170:20, 150:30, 120:30, 120:40, 120:60, 120:80 and 100:100) to give the triazole 58 as a colourless gum (74 mg, 72%). 1H NMR (CDCl3, 300 MHz) δ 8.19-7.88 (m, 16H, Bz), 7.69-7.15 (m, 35H, Bz and triazole-CH), 5.99 (dd or t, 1H, JH3-H4=9.9, JH4-H5=9.9, H4), 5.98 (dd or t, 1H, J=9.9, J=9.9, H4), 5.94 (dd or t, 1H, H4), 5.66 (dd, 1H, JH2(I)-H3(I)=3.1, JH1(I)H2(I)=1.6, H2I), 5.57 (dd, 1H, J3(III)-H4(III)=10.0, JH2(III)-H3(III)=3.1, H3III), 5.36 (d, 1H, JH1(II)-H2(II)=1.6, H1II), 5.28 (dd, 1H, JH2(II)-H3(II)=3.1, H2II), 5.21 (dd, 1H, JH1(III)-H2(III)=1.6, H2III), 5.04 (d, 1H, H1I), 4.94 (d, 1H, H1III), 4.70 (s, 2H, OCH2), 4.70-3.92 (m, 11H), 3.84 (dt or ddd, 1H, Jgem=9.9, J=6.3, J=6.3, OCH2), 3.50 (dt or ddd, 1H, J=5.5, J=5.5, OCH2), 3.37 (m, 1H, OCH-chol), 2.26 (m, 2H, CH2), 1.99-0.53 (m, 31H, cholestanyl), 0.90 (d, 3H, J=6.8, cholestanyl-CH3), 0.87 (d, 3H, J=6.8, cholestanyl-CH3), 0.86 (d, 3H, J=6.8, cholestanyl-CH3), 0.76 (s, 3H, cholestanyl-CH3), 0.64 (s, 3H, cholestanyl-CH3).