Compound 2g

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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 isopropyl 2-acetyl-2-(but-3-en-1-yl)hex-5-enoate 1g (33.8 mg, 0.134 mmol). After a reaction time of 48 h at −50 °C, the crude product 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 2g as a colorless oil (26.9 mg, 79%, er: 79:21). ¹H NMR (400 MHz, CDCl₃) δ5.83–5.73 (m, 1 H, CH=CH₂), 5.08 (qd, 1 H, J = 6.3, 6.3 Hz, OCH(CH₃)₂), 4.99 (d, 1 H, J = 17.2 Hz, CH=CH_cisH_trans), 4.93 (d, 1 H, J = 10.0 Hz, CH=CH_cisH_trans), 3.74 (s, 1 H, OH), 2.39–2.29 (m, 1 H, CH_aH_bCCO₂iPr), 2.09–1.81 (m, 5 H, CH₂CH=CH₂ + CH₃CH + CH_aH_bCH₂CH=CH₂ + CH₃CHCH_aH_b), 1.57–1.48 (m, 1 H, CH_aH_bCH₂CH=CH₂), 1.46–1.37 (m, 1 H, CH_aH_bCCO₂CH₃), 1.27 (d, 3 H, J = 6.3 Hz, OCH(CH₃)_a(CH₃)_b), 1.26 (d, 3 H, J = 6.3 Hz, OCH(CH₃)_a(CH₃)_b), 1.14–1.07 (m, 1 H, CH₃CHCH_aH_b), 1.04 (CH₃COH), 0.94 (d, 3 H, J = 6.4 Hz, CH₃CH); ¹³C NMR (100 MHz, CDCl₃) δ176.9 (CO₂iPr), 138.4 (CH=CH₂), 114.6 (CH=CH₂), 82.1 (COH), 68.4 (OCH(CH₃)₂), 43.2 (CH₃CH), 33.6 (CH₂CH₂CH=CH₂), 30.2 ((CH₂CCO₂iPr), 29.8 (CH₂CH=CH₂), 27.6 (CH₃CHCH₂), 21.9 (OCH(CH₃)_a(CH₃)_b), 21.7 (OCH(CH₃)_a(CH₃)_b), 17.5 (CH₃COH), 14.5 (CH₃CH); IR ν_max (neat/cm^-1): 3478, 2977, 2873, 2346, 1692, 1641, 1466, 1374, 1319, 1278, 1197, 1144, 1104, 992, 909, 841; HRMS (APCI) calcd for C₁₅H₂₇O₃, [M+H]⁺: 255.1955, found 255.1956. [α]²²_D = +9.7 (c = 0.28, CH₂Cl₂).

Enantiomeric purity of the product was determined by GC analysis (Chiraldex^® G-TA 30 m x 0.25 mm column, isothermal run at 80 °C, flow rate = 1.0 mL/min, retention time: 483.1 min (minor), 496.8 min (major); er: 79:21.