Page 9 of 13
The Journal of Organic Chemistry
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1/10 to 1/3) to afford the desired products. The chemical data of 2a-g, 6a-b and 8a were
20
reported in our previous communications.
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-(4-Butylchroman-4-yl)ethan-1-ol (4a): 60 mg, 85% yield, colorless oil. H NMR (500 MHz,
3
CDCl ) δ 7.16-7.18 (m, 1H), 7.06-7.09 (m, 1H), 6.85-6.89 (m, 1H), 6.80 (d, J = 8.5 Hz, 1H), 4.17 (t, J
= 5.5 Hz, 2H), 3.58-3.66 (m, 2H), 1.91-2.02 (m, 4H), 1.65-1.71 (m, 2H), 1.10-1.28 (m, 5H), 0.86 (t, J
13
=
4
6.5 Hz, 3H); C NMR (125 MHz, CDCl ) δ 154.7, 128.6, 127.3, 127.2, 120.3, 117.2, 62.9, 59.5,
3
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+
+
3.4, 41.6, 35.5, 31.8, 26.0, 23.3, 14.0; ESI-MS m/z 235.1 (M + H) ; HRMS calcd for C15
H
23
O
2
(M +
+
H) 235.1693, found 235.1688.
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-(4-Isobutylchroman-4-yl)ethan-1-ol (4b): 63 mg, 89% yield, colorless oil. H NMR (500
MHz, CDCl ) δ 7.18 (dd, J = 8.0, 1.0 Hz, 1H), 7.05-7.08 (m, 1H), 6.85-6.88 (m, 1H), 6.79 (d, J = 8.0
Hz, 1H), 4.15-4.18 (m, 2H), 3.56-3.64 (m, 2H), 1.94-2.04 (m, 4H), 1.56-1.74 (m, 3H), 1.30-1.34 (m,
3
1
3
1H), 0.90 (d, J = 6.5 Hz, 3H), 0.77 (d, J = 6.5 Hz, 3H); C NMR (125 MHz, CDCl
3
) δ 154.8, 128.8,
1
27.4, 127.2, 120.3, 117.2, 63.1, 59.5, 50.5, 44.3, 36.2, 31.8, 25.5, 25.0, 24.2; ESI-MS m/z 235.1
+
+
+
(
M + H) ; HRMS calcd for C15
23 2
H O (M + H) 235.1693, found 235.1683.
(
3-Methylchroman-3-yl)methanol (6c): 49.7 mg, 93% yield, white solid, melting point 75-77
o
1
C. H NMR (400 MHz, CDCl ) δ 7.09 (t, J = 7.6 Hz, 1H), 7.03 (d, J = 7.6 Hz, 1H), 6.86 (t, J = 7.6 Hz,
3
1
H), 6.81 (d, J = 7.6 Hz, 1H), 4.04 (dd, J = 10.8, 1.2 Hz, 1H), 3.78 (d, J = 10.8 Hz, 1H), 3. (d, J = 10.8
Hz, 1H), 3.44 (d, J = 10.8 Hz, 1H), 2.67 (d, J = 16.4 Hz, 1H), 2.53 (d, J = 16.4 Hz, 1H), 1.05 (s, 3H);
1
3
C NMR (125 MHz, CDCl
3
) δ 153.9, 130.2, 127.2, 120.9, 120.7, 116.5, 71.5, 67.3, 63.4, 34.2, 33.8,
+
+
+
20.3; ESI-MS m/z 179.1 (M + H) ; HRMS calcd for C11
15 2
H O (M + H) 179.1067, found 179.1059;
HPLC Chiralpak AS-H (hexane/i-PrOH = 97:3, 1.0 mL/min) τmajor = 19.3 min, τminor = 22.7 min.
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[
α]D -23.1 (c 1.0, CHCl , 73% ee).
3
o
(
3-Hexylchroman-3-yl)methanol (6d): 69.5mg, 93% yield, white solid, melting point 67-68 C.
H NMR (400 MHz, CDCl ) δ 7.09 (t, J = 7.6 Hz, 1H), 7.03 (d, J = 7.6 Hz, 1H), 6.84 (t, J = 7.6 Hz, 1H),
.81 (d, J = 7.6 Hz, 1H), 4.09 (dd, J = 10.8, 1.2 Hz, 1H), 3.78 (d, J = 10.8 Hz, 1H), 3.57 (d, J = 10.8 Hz,
H), 3.50 (d, J = 10.8 Hz, 1H), 2.63 (d, J = 16.4 Hz, 1H), 2.56 (d, J = 16.4 Hz, 1H), 1.45-1.49 (m, 1H),
1
3
6
1
1
1
3
3
.26-1.32 (m, 9H), 0.89 (t, J = 6.8 Hz, 3H); C NMR (125 MHz, CDCl ) δ 154.2, 130.2, 127.1, 121.0,
+
120.7, 116.5, 70.7, 64.2, 36.2, 33.2, 32.5, 31.8, 30.1, 22.8, 22.6, 14.1; ESI-MS m/z 249.2 (M + H) ;
+
2
+
HRMS calcd for C16
H
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O
(M + H) 249.1849, found 249.1849; HPLC Chiralpak AS-H
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(
hexane/i-PrOH = 90:10, 1.0 mL/min) τmajor = 6.1 min, τminor = 15.0 min. [α]
D
3
-21.0 (c 1.0, CHCl ,
6
7% ee).
(3-Benzylchroman-3-yl)methanol (6e): 73mg, 96% yield, white solid, melting point 77-78 C.
H NMR (400 MHz, CDCl ) δ 7.18-7.32 (m, 5H), 7.07-7.11 (m, 1H), 7.01 (d, J = 7.2 Hz, 1H),
.82-6.87 (m, 2H), 4.08 (dd, J = 10.8, 1.6 Hz, 1H), 3.85 (d, J = 10.8 Hz, 1H), 3.49 (d, J = 10.8 Hz, 1H),
.40 (d, J = 10.8 Hz, 1H), 2.83 (d, J = 13.2 Hz, 1H), 2.67 (d, J = 16.4 Hz, 1H), 2.65 (d, J = 13.2 Hz, 1H),
o
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3
6
3
13
2.49 (d, J = 16.4 Hz, 1H); C NMR (125 MHz, CDCl ) δ 154.0, 137.0, 130.6, 130.2, 128.3 127.3,
3
+
1
26.5, 120.8, 120.6, 116.5, 70.1, 63.9, 38.5, 37.4, 32.2; ESI-MS m/z 255.1 (M + H) ; HRMS calcd
+
+
19 2
for C17H O (M + H) 255.1380, found 255.1365; HPLC Chiralpak AD-H (hexane/i-PrOH = 95:5,
2
5
1
.0 mL/min) τminor = 14.0 min, τmajor = 15.3 min. [α]
(3-Isobutylchroman-3-yl)methanol (6f): 56.4 mg, 85% yield, oil. H NMR (500 MHz, CDCl
.08 (t, J = 7.5 Hz, 1H), 7.01 (d, J = 7.0 Hz, 1H), 6.84 (t, J = 7.5 Hz, 1H), 6.79 (d, J = 7.5Hz, 1H), 4.09
D
3
~ 0 (c 1.0, CHCl , 52% ee).
1
3
) δ
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(
dd, J = 11.0, 1.5 Hz, 1H), 3.75 (d, J = 11.0 Hz, 1H), 3.59 (d, J = 11.0 Hz, 1H), 3.51 (d, J = 11.0 Hz,
1
H), 2.68 (d, J = 16.5 Hz, 1H), 2.58 (d, J = 16.5 Hz, 1H), 1.78-1.86 (m, 2H), 1.41 (dd, J = 14.5, 6.5 Hz,
1
3
1H), 1.24 (dd, J = 14.5, 6.5 Hz, 1H), 0.98 (d, J = 6.5 Hz, 3H), 0.95 (d, J = 6.5 Hz, 3H); C NMR (125
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