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11.9 Hz, 1H), 5.58 (q, J = 6.8 Hz, 1H), 5.54 (d, J = 12.7 Hz, 1H), 5.51 (s, 1H), 4.07 (d, J = 13.8
Hz, 2H), 3.75 (s, 3H), 3.35 (d, J = 13.5 Hz, 1H), 2.41 (d, J = 14.3 Hz, 1H), 1.36 (d, J = 7.0 Hz,
3H), 0.96 (s, 9H), 0.21 (s, 3H), 0.20 (s, 3H).
Bz
N
MeO2C Bn
O
124 and 125
Aldehydes 124 and 125 : To a solution of allenyne 122c (20 mg, 0.050 mmol) in DCE (1 mL)
was added [Rh(CO)2Cl]2 (1 mg, 2 µmol) at rt. After 90 min, the reaction solution was directly
applied to a short silica gel column and eluted (hexanes-EtOAc, 3 : 1, v/v) to afford a mixture of
aldehydes 124 and 125 (10 mg, 50% by mass recovery).
CbzN
H
MeO 2C
O
N
Ph
O
Me
H
144
Diels-Alder cycloadduct 144. To a solution of triene 111f (0.018 g, 0.053 mmol), in toluene (1
mL), was added N-phenylmaleimide (31 mg, 0.23 mmol). The reaction was heated to reflux for 2
h. The solution was then cooled to rt, and directly applied to a silica gel column and purified by
flash chromatography (hexanes-EtOAc, 1 : 4, v/v then EtOAc) to afford 144 as a mixture of
diastereomers (30 mg, 83%). Further purification of the major diastereomer was performed using
HPLC (hexanes-EtOAc, 3 : 2, v/v, flow rate 3 mL/min, RI detector).
144 (major diastereomer, Rt = 26.1 min): 1 H NMR (500 MHz, CDCl3): δ 7.38-7.13 (m, 5 H),
7.31-7.22 (m, 5H), 7.20-7.16 (m, 3H), 7.04 (d, J = 7.2 Hz, 2H), 5.11 (d, J = 12.7 Hz, 1H), 5.01
(d, J = 12.7 Hz, 1H), 4.46 (d, J = 18.9 Hz, 1H), 3.54-2.51 (m, 2H), 3.42-3.39 (m, 1H), 3.36 (s,
3H), 3.29 (bs, 1H), 3.15 (dd, J = 8.8, 6.7 Hz, 1H), 3.03 (dd, J = 8.8, 5.6 Hz, 1H), 2.65 (dd, J =
200
O
O
N
Ph