Reaction Steps
A bomb liner was charged with (R)-RuBINAP catalyst (16.8 mg, 10.0 μmol). HCl (555 μL, 0.2N in MeOH) was added and the mixture was then sonicated for 15 sec. Then a solution of 69 (59.4 mg, 0.1 mmol) in MeOH (555 μL) was added and the mixture transferred to a Parr apparatus. The vessel was purged with H2 for 5 min and then pressurized to 1200 psi. After 17 h, the reaction was returned to atmospheric pressure and poured into a sat NaHCO3 aq solution. The aqueous layer was extracted three times with EtOAc. The combined organic extracts were dried over MgSO4 and concentrated under reduced pressure. The crude product was purified by flash chromatography (gradient hexane to hexane/EtOAc 88:12) to give 70 (dr>20:1 as judged by 1H NMR analysis) (47.6 mg, 80%) as a clear oil: 1H NMR (400 MHz, CDCl3) δ 1.06 (d, J=6.9 Hz, 3H), 1.11 (d, J=6.8 Hz, 3H), 1.14 (s, 3H), 1.18 (s, 3H), 1.47 (s, 9H), 2.05-2.12 (m, 1H), 2.35-2.40 (m, 1H), 3.31-3.37 (m, 2H), 3.51-3.54 (m, 2H), 4.11-4.14 (m, 1H), 4.46 (s, 2H), 4.72 (d, J=11.9 Hz, 1H), 4.80 (d, J=11.9 Hz, 1H), 5.05 (dd, J=5.0 and 6.7 Hz, 1H), 7.27-7.35 (m, 5H); 13C NMR (100 MHz, CDCl3) δ 12.0, 15.0, 19.3, 21.7, 28.0, 35.6, 37.5, 41.7, 51.8, 71.3, 73.0, 73.3, 80.6, 81.3, 94.7, 127.5, 127.7, 128.3, 138.2, 154.1, 172.4, 216; IR (film, NaCl, cm−1) 3849, 2974, 2879, 1758, 1701, 1454, 1368, 1248, 1152, 926, 734; LRMS (ESI) calcd for C27H39O8Cl3Na [M+Na+] 619.1, found 619.2; [α]23D=−13.0 (c=0.4, CHCl3).
