Reaction SMILES: [CH3:1][O:2][C:3]1[CH:92]=[CH:91][C:6]([CH2:7][O:8][C@@H:9]([C@@H:85]([CH3:90])/[CH:86]=[CH:87]\[CH:88]=[CH2:89])[C@@H:10]([CH3:84])[C@H:11]([O:76][Si:77]([C:80]([CH3:83])([CH3:82])[CH3:81])([CH3:79])[CH3:78])[CH2:12][CH2:13][C@H:14]([CH3:75])[CH2:15][C@H:16]([CH3:74])[C@@H:17]([O:66][Si:67]([C:70]([CH3:73])([CH3:72])[CH3:71])([CH3:69])[CH3:68])[C@@H:18]([CH3:65])/[CH:19]=[CH:20]\[C@@H:21]([O:57][Si:58]([C:61]([CH3:64])([CH3:63])[CH3:62])([CH3:60])[CH3:59])[CH2:22][C@H:23]([O:49][Si:50]([C:53]([CH3:56])([CH3:55])[CH3:54])([CH3:52])[CH3:51])[C@H:24]([CH3:48])/[CH:25]=[CH:26]/[CH2:27][O:28]C(C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=[CH:5][CH:4]=1>C(Cl)Cl.CO.[Zn+2].[Br-].[Br-]>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]([CH2:7][O:8][C@@H:9]([C@@H:85]([CH3:90])/[CH:86]=[CH:87]\[CH:88]=[CH2:89])[C@@H:10]([CH3:84])[C@H:11]([O:76][Si:77]([C:80]([CH3:83])([CH3:82])[CH3:81])([CH3:78])[CH3:79])[CH2:12][CH2:13][C@H:14]([CH3:75])[CH2:15][C@H:16]([CH3:74])[C@@H:17]([O:66][Si:67]([C:70]([CH3:71])([CH3:72])[CH3:73])([CH3:69])[CH3:68])[C@@H:18]([CH3:65])/[CH:19]=[CH:20]\[C@@H:21]([O:57][Si:58]([C:61]([CH3:62])([CH3:63])[CH3:64])([CH3:60])[CH3:59])[CH2:22][C@H:23]([O:49][Si:50]([C:53]([CH3:54])([CH3:55])[CH3:56])([CH3:52])[CH3:51])[C@H:24]([CH3:48])/[CH:25]=[CH:26]/[CH2:27][OH:28])=[CH:91][CH:92]=1
Reactant: C=C/C=C\[C@H](C)[C@H](OCc1ccc(OC)cc1)[C@@H](C)[C@@H](CC[C@H](C)C[C@H](C)[C@@H](O[Si](C)(C)C(C)(C)C)[C@@H](C)/C=C\[C@H](C[C@H](O[Si](C)(C)C(C)(C)C)[C@H](C)/C=C/COC(c1ccccc1)(c1ccccc1)c1ccccc1)O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C(C)(C)C
Agent: [Br-]
Agent: [Zn+2]
Solvent: ClCCl
Solvent: CO
Product: C=C/C=C\[C@H](C)[C@H](OCc1ccc(OC)cc1)[C@@H](C)[C@@H](CC[C@H](C)C[C@H](C)[C@@H](O[Si](C)(C)C(C)(C)C)[C@@H](C)/C=C\[C@H](C[C@H](O[Si](C)(C)C(C)(C)C)[C@H](C)/C=C/CO)O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C(C)(C)C
Reaction time: 4 h
Yield: 76597.5 %

Procedure:
ZnBr2 (0.41 g) in 1.2 mL of 5:1 CH2Cl2/MeOH was added dropwise for 30 min to a stirred solution of trityl compound 44 (0.24 g, 0.18 μmol) in 1.4 mL of 6:1 CH2Cl2/MeOH at 0° C. After 4 h, the reaction mixture was quenched with saturated aqueous NaHCO3 (20 mL) and extracted with Et2O (2×10 mL). The organic phase were separated, dried with MgSO4, filtered and concentrated. The residue was purified by flash chromatography (EtOAc/hexane 1:9) to yield 45 (0.15 g, 77%) as a colorless oil: IR (CHCl3) 3432, 2956, 2856, 1613, 1514, 1471, 1462, 1360, 1250, 1082, 835, 773 cm−1; 1H NMR (300 MHz, CDCl3) δ 7.29 (m, 2H), 6.88 (m, 2H), 6.58 (ddd, J=16.9, 10.6, 10.6 Hz, 1H), 6.00 (t, J=11.0 Hz, 1H), 5.63 (m, 3H), 5.38 (t, J=11.0 Hz, 1H), 5.27 (dd, J=11.2, 8.3 Hz, 1H), 5.17 (d, J=16.8 Hz, 1H), 5.10 (d, J=10.3 Hz, 1H), 4.53 (m, 3H), 4.08 (d, J=4.4 Hz, 2H), 3.90 (m, 1H), 3.81 (s, 3H), 3.62 (m, 1H), 3.33 (m, 2H), 2.99 (ddd, J=10.0, 6.8, 3.2 Hz, 1H), 2.57 (m, 1H), 2.39 (m, 1H), 1.63 (m, 3H), 1.42 (m, 3H), 1.28 (m, 5H), 1.11 (d, J=6.8 Hz, 3H), 0.97 (d, J=6.8 Hz, 3H), 0.96 (d, J=6.9 Hz, 3H), 0.93 (s, 9H), 0.91 (s, 18H), 0.89 (m, 3H), 0.88 (s, 9H), 0.81 (d, J=6.7 Hz, 3H), 0.80 (d, J=6.2 Hz, 3H), 0.10 (s, 3H), 0.09 (s, 3H), 0.08 (s, 6H), 0.06 (s, 3H), 0.05 (s, 6H), 0.03 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 159.0, 146.9, 135.2, 134.6, 133.0, 132.7, 132.3, 131.4, 129.2, 129.1, 128.9, 127.93, 127.90, 127.2, 84.4, 80.0, 75.0, 72.8, 72.2, 66.6, 63.9, 55.2, 42.4, 41.8, 41.7, 40.5, 35.9, 35.2, 34.6, 32.6, 31.6, 30.5, 26.3, 25.99, 25.96, 25.93, 20.2, 19.2, 18.8, 18.5, 18.2, 18.1, 15.1, 13.2, 9.2, −3.0, −3.3, −3.6, −3.7, −4.2, −4.4, −4.5; LRMS (ESI) 1109.8 [M+Na]+, 823.6, 691.5, 559.4; HRMS (ESI) calcd for C62H118O7Si4Na 1109.7852 [M+Na]+, found 1109.7897; [α]20D+1.6 (c 0.94, CHCl3).