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3.00 (d, J = 13.6 Hz, 0.5H), 1.64-1.60 (m, 3H), 1.45 (dd, J = 7.1, 3.2 Hz, 3H).
BzN
O
N-(1-Benzyl-1-but-2-ynyloxymethylpenta-2,3-dienyl)-N-but-2-ynylbenzamide (173). To a
solution of amide-alcohol 172 (170 mg, 0.554 mmol) in DMF (1.5 mL) was added NaH (110 mg
of a 60% dispersion in mineral oil, 2.75 mmol), followed by 1-bromo-2-butyne (145 µL, 1.65
mmol) at rt. The reaction mixture was stirred at rt for 30 min when it was quenched by pouring
into water. The aqueous mixture was extracted with EtOAc, the organic layers were combined,
dried over MgSO4, and concentrated under vacuum. The crude oily residue was purified by flash
chromatography to afford 173 (150 mg, 66%).
1 H NMR (300 MHz, CDCl3): δ 7.54-7.23 (m, 10H), 5.83-5.79 (m, 1H), 5.35-5.21 (m, 1H), 4.28-
4.14 (m, 3H), 3.93-3.73 (m, 4H), 3.25 (d, J = 13.0 Hz, 0.5H), 3.16 (d, J = 13.1 Hz, 0.5H), 1.86 (t,
J = 2.2 Hz, 3H), 1.71 (dd, J = 7.0, 3.2 Hz, 0.5H), 1.67-1.64 (m, 6H).
Bz
Bn
O
(6-But-2-ynyloxymethyl-3-ethylidene-6-methyl-4-vinyl-3,6-dihydro-2H-pyridin-1-yl)-
N
phenylmethanone (174). To a solution of allene-diyne 173 (140 mg, 0.340 mmol) in toluene
(1.5 mL) was added [Rh(CO)2Cl]2 (7 mg, 18 µmol) at rt. The reaction mixture was stirred at rt
for 1 h and then directly applied to a silica gel column. Elution (hexanes-EtOAc, 9 : 1, v/v)
afforded 174 (112 mg, 80%) as a pale yellow oil.
1 H NMR (300 MHz, CDCl3): δ 7.38-7.19 (m, 10H), 6.32 (dd, J = 17.2, 10.7 Hz, 1H), 5.80 (s,
Bn
174
220
•
173
H