Download (3249Kb) - D-Scholarship@Pitt - University of Pittsburgh

MeO 2C
O
O
O
N
H
N R1 O
N
Ph
(5-Ethoxy-7,12c-dimethyl-3,10,12-trioxo-11-phenyl-6,7,9,9a,10,11,12,12a,12b,12c-
decahydro-5H-2,4-dioxa-3a,11-diazadicyclopenta[a,l]phenanthren-1-ylideneamino)-acetic
acid methyl ester (157a). To a solution of unsaturated amide 156a (10 mg, 18 µmol) in 1,2-
dichloroethane (100 µL), were added ethyl vinyl ether (50 µL) and Eu(fod)3 (2 mg, 2 µmol). The
reaction vessel was then sealed and placed in a sonicator (Branson 2510), and sonication was
continued at rt for 6h. The reaction mixture was purified by flash chromatography (hexanes-
EtOAc, 1 : 1, v/v) to afford 157a (11 mg, >95%).
1 H NMR (300 MHz, CDCl3): δ 7.39-7.28 (m, 6H), 7.14-7.07 (m, 4H), 5.72-5.65 (m, 1H), 5.30 (t,
J = 2.6 Hz, 1H), 4.35 (d, J = 18.1 Hz, 1H), 4.20 (d, J = 18.1 Hz, 1H), 4.21 (dd, J = 8.8, 4.4 Hz,
1H), 3.87-3.76 (m, 1H), 3.79 (s, 3H), 3.58 (dq, J = 9.9, 7.1 Hz, 1H), 3.45-3.43 (m, 1H), 3.42 (d, J
= 13.4 Hz, 1H), 3.09 (d, J = 13.4 Hz, 1H),3.07 (bs, 1H), 2.99 (dd, J = 15.2, 7.7 Hz, 1H), 2.81 (dt,
J = 10.3, 6.9 Hz, 1H), 2.41-2.31 (m, 1H), 2.28 (ddd, J = 13.9, 6.7, 2.5 Hz, 1H), 1.86-1.77 (m,
1H), 1.23 (d, J = 6.7 Hz, 3H), 0.93 (t, J = 7.1 Hz, 3H); 13 C NMR (75 MHz, toluene-d 8 ): δ 177.7,
176.1, 170.1, 156.0, 146.4, 137.9, 134.5, 132.9, 132.7, 130.7, 128.7, 128.1, 126.8, 116.0, 99.6,
97.4, 66.1, 64.5, 51.4, 40.0, 45.0, 44.7, 42.1, 41.8, 37.0, 26.0, 21.4, 21.2, 20.4, 19.7, 14.7; IR
(thin film): ν 2594, 1822, 1735, 1712 cm -1 ; MS m/z (%) 649 (50), 648 (100), 576 (15); HRMS
157a
calcd. for C35H35N3O8Na [M+23] + m/z 648.2322, found 648.2310.
214
OEt
O