Compound 2i

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

Prepared according to general procedure 2 outlined for compound 2a from methyl 1-acetylcyclohept-4-ene-1-carboxylate 1i (26.3 mg, 0.134 mmol). After a reaction time of 48 h at −40 °C, the crude product (> 99:1 dr) was purified by column chromatography (hexane/EtOAc 98:2 to 95:5 to elute the product, then 80:20 to elute ligand 3f) to afford diastereopure 2i as a colorless oil (22.1 mg, 83%, er: 93:7). ¹H NMR (400 MHz, CDCl₃) δ3.70 (CO₂CH₃), 3.57 (s, 1 H, OH), 2.28–2.10 (m, 2 H, CHCH₂CH_aH_bCCO₂CH₃ + CHCH_aH_bCH₂CCO₂CH₃), 2.00–1.94 (m, 1 H, CH), 1.80–1.49 (m, 6 H, CHCH₂CH₂CH₂CCO₂CH₃ + CHCH₂CH_aH_bCCO₂CH₃ + CHCH_aH_bCH₂CH₂CCO₂CH₃ + CHCH₂CH₂CH₂CCO₂CH₃), 1.46–1.37 (m, 2 H, CHCH_aH_bCH₂CH₂CCO₂CH₃ + CHCH_aH_bCH₂CCO₂CH₃), 1.38 (s, 3 H, CH₃COH); ¹³C NMR (100 MHz, CDCl₃) δ177.7 (CO₂CH₃), 81.9 (COH), 55.3 (CCO₂CH₃), 51.9 (CO₂CH₃), 45.4 (CH), 32.6 (CHCH₂CH₂CCO₂CH₃), 31.4 (CHCH₂CH₂CH₂CCO₂CH₃), 28.4 (CHCH₂CH₂CH₂CCO₂CH₃), 26.9 (CHCH₂CH₂CCO₂CH₃), 19.6 (CH₃COH), 17.1 (CHCH₂CH₂CH₂CCO₂CH₃); IR ν_max (neat/cm^-1): 3504, 2930, 2870, 1708, 1464, 1446, 1433, 1375, 1311, 1271, 1234, 1212, 1190, 1174, 1126, 1084, 1060, 1019, 977, 929, 881, 852, 815, 772, 738, 723; HRMS (APCI) calcd for C₁₁H₁₉O₃, [M+H]⁺: 199.1329, found 199.1329. [α]²²_D = +14.6 (c = 0.26, CH₂Cl₂).

Enantiomeric purity of the product was determined by GC analysis (ChiraSil^® DEX CB 25 m x 0.25 mm column, isothermal run at 90 °C, flow rate = 1.0 mL/min, retention time: 242.6 min (minor) and 262.1 min (major); er: 93:7.