Compound 6da

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InChIKey XWKLQKBHAMZHTI-DOTOQJQBSA-N

Compound data: CIF

Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

Following the general procedure for compound 6ba, 21 mg of 7 (0.025 mmol, 0.025 equiv), 102 µL of benzaldehyde (1.0 mmol), 175 µL of N,N-diisopropylethylamine (1.0 equiv, 1.0 mmol) and 130 µL of SiCl₄ (1.1 mmol, 1.1 equiv) were combined with 0.82 mL of a 1.47 M solution of 4d (1.2 mmol, 1.2 equiv) in CH₂Cl₂ to yield after column chromatography (25 g SiO₂ gel, Ø 20 mm column, hexanes/EtOAc gradient (12:1, 260 mL to 10:1, 220 mL)) and drying in vacuo (Abderhalden, 34 °C, 0.3 mm Hg ) 253 mg of 6da (92%) as a white needles. The diastereomeric ratio was determined to be 98:2 by ¹H NMR (500 MHz) analysis of the crude product. Analytically pure material was obtained after recrystallization from hot EtOAc (ca. 0.25 mL) and hexanes (ca. 1.5 mL). mp: 85-86 °C ; ¹H NMR: (500 MHz, CDCl₃) 7.50 (d, J=8.0 Hz, 2 H, HC(5)), 7.41 – 7.30 (m, 3 H, HC(6, 7)), 4.80 (d, J=4.1 Hz, 1 H, HC(3)), 3.08 (d, J=4.6 Hz, 1 H, OH), 1.97 – 1.82 (m, 2 H, HC(9) and H₂C(8)), 1.58 (dd, J=14.1, 5.1 Hz, 1 H H₂C(8)), 1.45 (s, 9H, H₃C(12)), 1.01 (d, J=6.4 Hz, 3 H, H₃C(10)), 0.99 (d, J=6.5 Hz, 3 H, H₃C(10)); ¹³C NMR: (125 MHz, CDCl₃); 137.2 (C(4)), 128.6 (C(7)), 128.1 (C(5, 6)), 127.9 (C(5, 6)), 120.4 (C(1)), 78.9 (C(2)), 77.0 (C(11)), 76.9 (C(3)), 44.8 (C(8)), 29.6 (C(12)), 24.6 (C(9, 10)), 24.2 (C(9, 10)), 23.9 (C(9, 10)); IR: (KBr Pellet) 3470 (s), 3036 (w), 3064 (w), 2981 (s), 2963 (s), 2868 (s), 1498 (w), 1473 (m), 1453 (m), 1406 (m), 1367 (s), 1285 (m), 1271 (m), 1187 (m), 1138 (m), 1084 (s), 1057 (s), 1029 (m), 1003 (w), 954 (w), 897 (m), 860 (m), 748 (m), 699 (s); MS: (ESI) 298.1 (65.6, M+Na⁺), 288.0 (56.2), 272.1 (22.5), 263.1 (18.9), 231.0 (11.8), 194.1 (14.7), 193.1 (100.0), 175.1 (45.5), 158.0 (26.6), 119.0 (31.9), 91.0 (52.6); HRMS: calcd for C₁₇H₂₅NO₂Na⁺: 298.1788, found: 298.1783; TLC: 0.22 (hexane/EtOAc, 9:1) [CAM]; Opt. Rot.: [α]_D²⁴ –3.8 (c=1.6, EtOH); SFC: (2S,3R)-6da, t_R 6.6 min (0.4%); (2R,3S)-6da, t_R 7.5 min (99.6%), (Chiralpak OD, 125 bar, 2% MeOH in CO₂, 2.5 mL/min, 210 nm, 40 °C); Analysis: C₁₇H₂₅NO₂ (275.385) Calcd: C, 74.14; H, 9.15; N, 5.09% Found: C, 74.39; H, 9.41; N, 5.34%.