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H
MeO 2C
•
H
Bn
NHBoc
tert-Butyl-2-(methoxycarbonyl)-1-phenylhexa-3,4-dien-2-ylcarbamate (65f). Prepared by
following the general procedure E, using: Step 1: LDA (74.3 mmol), 64f (11.6 g, 29.7 mmol),
ZnCl2 (71 mL of a 0.5 M solution in THF, 35.6 mmol). Step 2: KHCO3 (7.4 g, 74 mmol), MeI
(4.6 mL, 74 mmol). Step 3: TBAF (44.5 mL of a 1.0 M solution in THF, 44.5 mmol).Yield 65f
(5.9 g, 60%, 3 steps). Notes: Simultaneous dropwise addition of ZnCl2 and 64f to LDA was
performed at -78 °C. The solution of 64f in THF was cooled to -78 °C and added to LDA via a
canula.
1 H NMR (300 MHz, CDCl3): δ 7.26-7.24 (m, 3H), 7.13-7.11 (m, 2H), 5.40 (bs, 1H), 5.28 (quin,
J = 6.8 Hz, 1H), 5.19 (bs, 1H), 3.78 (s, 3H), 3.45 (d, J = 13.2 Hz, 1H), 3.42 (d, J = 13.2 Hz, 1H),
1.68 (dd, J = 6.9, 3.0 Hz, 3H), 1.48 (s, 9H); 13 C NMR (75 MHz, CDCl3): δ 203.1, 172.4, 154.1,
136.1, 130.3, 128.0, 126.7, 93.5, 91.3, 79.5, 62.5, 52.5, 40.6, 28.3, 13.9; IR (thin film): ν 3430,
2978, 1969, 1741, 1717, 1494 cm -1 ; MS m/z (%) 332 (7), 276 (30), 184 (50), 91 (44), 57 (100);
EI-HRMS calcd for C19H25NO4 m/z [M] + 331.1784; found 331.1781.
TMS
MeO 2C
65f
•
67f
H
Bn
NHBoc
tert-Butyl-2-(methoxycarbonyl)-3-(trimethylsilyl)-1-phenylhexa-3,4-dien-2-ylcarbamate
(67f). 1 H NMR (300 MHz, CDCl3): δ 7.41-7.36 (m, 3H), 7.21-7.18 (m, 2H), 5.65 (bs, 1H), 5.20
(q, J = 7.0 Hz, 1H), 3.90 (s, 3H), 3.89 (d, J = 13.4 Hz, 1H), 3.54 (d, J = 13.4 Hz, 1H), 1.91 (d, J
= 6.9 Hz, 3H), 1.65 (s, 9H); 13 C NMR (75 MHz, CDCl3): δ 208.3, 173.1, 153.4, 136.8, 130.0,
163