E
T. Hiraoka et al.
Paper
Synthesis
2f
1-(2-Azido-1-phenylethoxy)-2,2,6,6-tetramethylpiperidine (7)10b
1H NMR (400 MHz, CDCl3): δ = 1.28–1.37 (m, 10 H), 1.58–1.62 (m, 2
H), 1.72–1.77 (m, 2 H), 2.28 (t, J = 7.8 Hz, 2 H), 3.61 (dd, J = 6.8, J = 13.2
Hz, 1 H), 3.65 (s, 3 H), 3.72 (dd, J = 6.0, J = 13.2 Hz, 1 H), 4.05–4.09 (m,
1 H).
13C NMR (100 MHz, CDCl3): δ = 25.0, 28.7, 29.1, 29.2 (2 C), 29.3, 32.4,
34.2, 37.2, 51.6, 59.1, 174.4.
Me3SiN3 (0.24 mL, 1.8 mmol) was added to a solution of IF5–pyridine–
HF (193 mg, 0.6 mmol) and TEMPO (140 mg, 0.7 mmol) in CH2Cl2 (5
mL) at 0 °C. When gas evolution ceased, a solution of styrene (31 mg,
0.3 mmol) in CH2Cl2 (2 mL) was added and the mixture was stirred at
r.t. for 2 h. The mixture was poured into H2O (15 mL) and extracted
with CH2Cl2 (3 × 20 mL). The combined organic layers were washed
with sat. aq NaHCO3 (20 mL), dried (MgSO4), and concentrated. The
product was isolated by column chromatography [silica gel, hexane–
Et2O (20:1)] as a pale yellow liquid, along with 5% of 2a; yield: 70 mg
(0.23 mmol, 77%).
3f
1H NMR (400 MHz, CDCl3): δ = 3.20–3.28 (m, 2 H, CH2I), 3.35–3.41 (m,
1 H, CHN3).
13C NMR (100 MHz, CDCl3): δ = 8.6 (CH2I), 62.8 (CHN3).
IR (neat): 2932, 2103, 1259 cm–1
1H NMR (400 MHz, CDCl3): δ = 0.68 (br s, 3 H), 1.03 (br s, 3 H), 1.19 (br
s, 3 H), 1.32 (br s, 3 H), 1.25–1.49 (m, 6 H), 3.64 (dd, J = 4.4, J = 12.8 Hz,
1 H), 3.73 (dd, J = 6.8, J = 12.4 Hz, 1 H), 4.82 (dd, J = 4.4, J = 6.8 Hz, 1 H),
7.32–7.36 (m, 5 H).
6-Azido-5-iodohexyl Acetate (2g) and 5-Azido-6-iodohexyl Acetate
(3g)
Isolated as a mixture of 2g and 3g in a ratio of 7.5:1 by column chro-
matography [silica gel, hexane–Et2O (6:1)] as a pale yellow liquid;
yield: 106 mg (0.34 mmol, 68%).
13C NMR (100 MHz, CDCl3): δ =17.2, 20.4 (2 C), 34.1, 34.5, 40.5 (2 C),
55.3, 60.2 (2 C), 84.9, 127.7 (2 C), 128.0, 128.3 (2 C), 140.8.
IR (neat): 2949, 2102, 1737, 1244 cm–1
.
3-Azido-2-iodopropyl 2,3,4,6-Tetra-O-acetyl-β-D-galactopyrano-
side (9)
2g
Isolated as a pale yellow liquid by column chromatography [silica gel,
hexane–Et2O (1:2)] as a mixture of two diastereomers in a 1:1 ratio;
yield: 175 mg (0.32 mmol, 63%).
1H NMR (400 MHz, CDCl3): δ = 1.35–1.84 (m, 6 H) 2.06 (s, 3 H), 3.59
(dd, J = 13.2, J = 6.8 Hz, 1 H), 3.73 (dd, J = 13.2, J = 6.4 Hz, 1 H), 4.01–
4.09 (m, 3 H).
13C NMR (100 MHz, CDCl3): δ = 21.1, 25.9, 27.8, 31.7, 36.7, 59.0, 64.1,
171.2.
IR (neat): 1751, 1226, 908 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 1.98 (s, 3 H), 2.04 (s, 1.5 H), 2.05 (s, 1.5
H), 2.07 (s, 1.5 H), 2.08 (s, 1.5 H), 2.15 (s, 3 H), 3.71–3.73 (m, 2 H),
3.76–3.80 (m, 1 H), 3.90 (t, J = 6.8 Hz, 1 H), 4.05–4.23 (m, 4 H), 4.48–
4.52 (m, 1 H), 5.03–5.49 (m, 1 H), 5.17–5.21 (m, 1 H), 5.38 (d, J = 2.4
Hz, 1 H).
HRMS (EI): m/z calcd for C8H15IN3O2: 312.02035; found: 312.0244.
3g
1H NMR (400 MHz, CDCl3): δ = 3.22–3.25 (m, 2 H, CH2I), 3.35–3.41 (m,
1 H, CHN3).
13C NMR (100 MHz, CDCl3): δ = 8.3 (CH2I), 62.6 (CHN3).
13C NMR (100 MHz, CDCl3): δ = 20.7, 20.8, 20.9, 21.1, 25.9 (0.5 C), 26.0
(0.5 C), 54.8 (0.5 C), 55.3 (0.5 C), 61.2 (0.5 C), 61.3 (0.5 C), 66.9, 68.5
(0.5 C), 68.6 (0.5 C), 70.7 (0.5 C), 70.8 (0.5 C), 70.9, 71.7 (0.5 C), 71.9
(0.5 C), 101.0 (0.5 C), 101.5 (0.5 C), 169.4 (0.5 C), 169.5 (0.5 C), 170.1,
170.2, 170.4.
Ethyl 3-Azido-2-iodopropionate (2h)
HRMS (FTMS): m/z calcd for C17H24IN3NaO10: 580.03986, found:
580.03983.
Isolated by column chromatography [silica gel, hexane–Et2O (20:1)]
as a pale yellow liquid; yield: 93 mg (0.34 mmol, 68%).
IR (neat): 2983, 2107, 1733, 1274, 1265, 499 cm–1
.
2-Iodo-3-(5-phenyl-1H-1,2,3-triazol-1-yl)propyl 2,3,4,6-tetra-O-
acetyl-β-D-galactopyranoside (10)
1H NMR (400 MHz, CDCl3): δ = 1.29 (t, J = 7.4 Hz, 3 H), 3.61 (dd, J = 5.6,
J = 12.8 Hz, 1 H), 3.91 (dd, J = 10.0, J = 12.8 Hz, 1 H), 4.23–4.31 (m, 2 H),
4.38 (dd, J = 10.0, J = 5.6 Hz, 1 H).
PhC≡CH (20 mg, 0.2 mmol), CuI (7.5 mg, 0.04 mmol), and DIPEA (252
mg, 1.95 mmol) were added successively to pyranoside 9 (84 mg, 0.15
mmol) in a mixture DMF (2 mL) and THF (2 mL) at r.t. under N2. The
mixture was stirred at 35 °C for 24 h then poured into H2O (20 mL)
and extracted with Et2O (3 × 20 mL). The combined organic layers
were washed with H2O (20 mL), dried (MgSO4), and concentrated.
Pyranoside 10 was isolated as a mixture of two diastereomers in a ra-
tio of 1:1 by column chromatography [silica gel, hexane–Et2O (1:5)] as
a pale yellow liquid; yield: 51.2 (0.079 mmol, 53%).
13C NMR (100 MHz, CDCl3): δ = 13.7, 15.4, 54.6, 62.4, 169.7.
HRMS (EI): m/z calcd for C5H9IN3O2: 269.97340; found: 269.97398.
(5-Azido-1-iodopent-3-en-1-yl)benzene (6)
Isolated by column chromatography [silica gel, hexane–Et2O (40:1)]
as a pale yellow liquid; yield: 63 mg (0.2 mmol, 40%).
IR (neat): 2918, 2100, 492 cm–1
1H NMR (400 MHz, CDCl3): δ = 2.90–2.97 (m, 1 H), 3.09–3.14 (m, 1 H),
3.67 (d, J = 4.4 Hz, 2 H), 5.07 (t, J = 7.2 Hz, 1 H), 5.62–5.65 (m, 2 H),
7.23–7.41 (m, 5 H).
IR (neat): 2925, 1749, 1223 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 1.97 (s, 1.5 H), 1.98 (s, 1.5 H), 1.99 (s,
1.5 H), 2.01 (s, 1.5 H), 2.10 (s, 1.5 H), 2.13 (s, 1.5 H), 2.14 (s, 1.5 H),
2.16 (s, 1.5 H), 3.72–3.83 (m, 1 H), 3.90–3.94 (m, 1 H), 4.08–4.15 (m, 2
H), 4.48–4.61 (m, 1 H), 4.67–4.74 (m, 1 H), 4.81–4.91 (m, 1 H), 5.00–
5.07 (m, 1 H), 5.22–5.29 (m, 3 H), 5.38–5.40 (m, 1 H), 7.31–7.34 (m, 1
H), 7.42 (dd, J = 8.4, J = 7.6 Hz, 2 H), 7.83 (d, J = 7.6 Hz, 2 H), 7.90 (d, J =
10.4 Hz, 1 H).
13C NMR (100 MHz, CDCl3): δ = 31.9, 44.0, 52.5, 126.6, 127.2 (2 C),
128.3, 128.9 (2 C), 133.5, 143.3.
HRMS (EI): m/z calcd for C11H12IN3: 313.00759; found: 313.00884.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2016, 48, A–F