9832
X. Jiang et al. / Tetrahedron 66 (2010) 9828e9834
Data for 1H NMR and melting point was consistent with that
reported in the literature.10c
the three gold catalysts. To a solution of 5a (100.1 mg, 0.6 mmol) in
acetonitrile (3 mL), 5 mol % HAuCl4 was added. The solution was
stirred under argon at 40 ꢁC for 20 h. A sample of the reaction
mixture was taken and the solvent was evaporated in vacuo to give
a crude yellow oil. The reaction was repeated for 5a with AuCl and
AuCl3, and for the other diols with the three catalysts. The reactions
were also tested at a higher temperature (80 ꢁC).
3.5. Synthesis of 1-(4-methoxyphenyl)pentane-1,5-diol 5e
The procedure described for 5a was followed utilising methyl-5-
methoxyphenyl-5-oxopentanoate (1.00 g, 4.24 mmol, 1.0 equiv)
and LiAlH4 (2.0 M) in anhydrous THF (8.00 mL, 16.0 mmol,
3.7 equiv). Product 5e (0.843 g, 94.7%) was isolated as a colourless
oil. MS: m/z (ESIþ): 233.0 ([MþNa]þ); HRMS: calcd for C12H18NaO3:
233.1147 ([MþNa]þ). Found 233.1148 ([MþNa]þ); nmax 3328 (br),
3.9.1. 2-Phenyltetrahydrofuran 4a. A crude yellow oil was isolated.
dH (300 MHz, CDCl3) 7.33e7.20 (5H, m, Ph), 4.90 (1H, t, J 7.1,
CHOCH2), 4.08 (1H, q, J 6.9, OCHH), 3.95 (1H, q, J 6.9, OCHH),
2.38e2.26 (1H, m, CH), 2.1 (2H, quin, J 7.0, CH2), 1.87e1.74 (1H, m,
CH). NMR data were consistent with those reported.18
2936 (s), 1611 (m), 1511 (s), 1239 (s) and 830 (s) cmꢀ1
; dH (300 MHz,
CDCl3) 7.27 (2H, d, J 8.6, ArH), 6.89 (2H, d, J 8.6, ArH), 4.64 (1H, t, J
6.0, ArCHOH), 3.80 (3H, s, OCH3), 3.63 (2H, dt, J 6.0, 3.9, CH2OH),
1.90e1.75 (2H, m, HCOHCH2), 1.63e1.53 (2H, m, CH2CH2OH),
1.41e1.25 (2H, m, CH2CH2CH2); dC (75 MHz, CDCl3) 158.4, 136.3,
126.5, 113.2, 73.5, 62.0, 54.7, 37.9, 31.8, 21.4.
3.9.2. 2-Phenyltetrahydropyran 4b. A crude yellow oil was isolated.
dH (300 MHz, CDCl3) 7.36e7.20 (5H, m, Ph), 4.32 (1H, dd, J 10.6, 2.4,
CHOCH2), 4.14 (1H, dd, J 11.2, 3.8, OCHH), 3.60 (1H, dt, J 11.2, 2.5,
OCHH), 2.02e1.90 (2H, m, CH2), 1.86e1.79 (2H, m, CH2), 1.70e1.55
(2H, m, CH2). NMR data were consistent with those reported.19
3.6. Synthesis of 1-(4-methoxyphenyl)hexane-1,6-diol 5f
The procedure described for 5a was followed utilising methyl-6-
methoxyphenyl-6-oxohexanoate (1.00 g, 4.00 mmol, 1.0 equiv) and
LiAlH4 (2.0 M) in anhydrous THF (8.00 mL, 16.0 mmol, 3.7 equiv).
The product 5f (0.887 g, 98.9%) was formed as white crystals. Mp
45 ꢁC; MS: m/z (ESIþ): 247.1 ([MþNa]þ); HRMS: calcd for
C13H20O3Na: 247.1297 ([MþNa]þ). Found 247.1305 ([MþNa]þ); nmax
3.9.3. 2-Phenyltetrahydrooxepine 4c. Due to poor conversions, the
crude yellow oil could not be fully characterised. Emerging peaks
show the presence of two products. A five aryl hydrogen multiplet
and an eight alkyl hydrogen multiplet for both products are as-
sumed to be under the substrate multiplets at 7.40e7.10 ppm and
2.20e1.20 ppm, respectively (see Supplementary data). Product 4c:
dH (300 MHz, CDCl3) 4.58 (1H, dd, J 6.9, 2.7, CHOCH2), 4.00e3.90
(1H, m, OCHH), 3.68e3.75 (1H, m, OCHH). Unknown product: dH
(300 MHz, CDCl3) 4.15 (1H, dd, J 5.6, 4.2, CHOCH2), 3.30e3.15 (2H,
m, OCH2). The unknown product may be a dimer similar to that
formed from 5f but insufficient quantities were obtained to char-
acterise it.
3405 (br), 2942 (s), 1612 (w), 1515 (m), 1026 (s) and 831 (s) cmꢀ1
; dH
(300 MHz, CDCl3) 7.23 (2H, d, J 8.7, ArH), 6.84 (2H, d, J 8.7, ArH), 4.60
(1H, t, J 7.0, ArCHOH), 3.80 (3H, s, OCH3), 3.60 (2H, t, J 6.5, CH2OH),
2.05 (1H, br s, OH) 1.85e1.60 (2H, m, HCOHCH2), 1.60e1.50 (2H, m,
CH2CH2OH), 1.45e1.28 (4H, m, CH2(CH2)2CH2); dC (75 MHz, CDCl3)
158.4, 136.4, 126.5, 113.2, 73.5, 62.2, 54.7, 38.3, 32.0, 25.0, 25.0.
3.7. Synthesis of 1-cyclohexylbutane-1,4-diol 5g
3.9.4. 2-(4-Methoxyphenyl)tetrahydrofuran 4d. Product 4d was
isolated as a colourless oil. MS: m/z (ESIþ): 201.0 ([MþNa]þ); HRMS:
calcd for C11H14NaO2: 201.0886 ([MþNa]þ). Found 201.0886
([MþNa]þ); nmax 2950 (b), 1613 (m), 1512 (s), 1244 (s) and 829 (s)
The procedure described for 5a was followed utilising methyl-4-
cyclohexyl-4-oxobutanoate (0.501 g, 2.53 mmol, 1.0 equiv) and
LiAlH4 (2.0 M) in anhydrous THF (4.80 mL, 9.60 mmol, 3.7 equiv).
The reaction mixture was stirred for 2 h. The product 5g (0.380 g,
87.3%) was formed as white crystals. Mp 50e52 ꢁC; MS: m/z (ESIþ):
195.1 ([MþNa]þ); HRMS: calcd for C10H20O2Na: 195.1351
([MþNa]þ). Found 195.1356 ([MþNa]þ); nmax 3275 (br), 2933 (s),
cmꢀ1
; dH (300 MHz, CDCl3) 7.25 (2H, d, J 8.6, ArH), 6.86 (2H, d, J 8.8,
ArH), 4.82 (1H, t, J 7.1, OCHAr), 4.07 (1H, dt, J 8.2, 6.9, OCHH), 3.90
(1H, dt, J 7.6, 6.4, OCHH), 3.80 (3H, s, OCH3), 2.33e2.22 (1H, m, CH2),
2.05e1.95 (2H, m, CH2), 1.84e1.72 (1H, m, CH2); dC (75 MHz, CDCl3)
158.8, 135.3, 127.0, 113.7, 80.5, 68.5, 55.3, 34.5, 26.1. Data were
consistent with those reported.12a
1438 (m) and 1044 (s) cmꢀ1
; dH (300 MHz, CDCl3) 3.70e3.60 (2H,
m, CH2OH), 3.41e3.34 (1H, m, CHOH), 2.05 (1H, br s, OH), 1.90e0.90
(16H, m, alkyl-CHþOH); dC (75 MHz, CDCl3) 76.3, 63.2, 43.8, 31.1,
29.5, 29.2, 28.0, 26.5, 26.3, 26.2.
3.9.5. 2-(4-Methoxyphenyl)tetrahydropyran 4e. Product 4eþwas iso-
lated as white crystals. Mp 44e45 ꢁC; MS: m/z<GK> (ESI ): 215.3
([MþNa]þ); HRMS: calcd for C12H16NaO2: 215.1039 ([MþNa]þ).
Found 215.1043 ([MþNa]þ); nmax 2936 (m), 1611 (w), 1511 (m), 1248
(s) and 817 (s); dH (300 MHz, CDCl3) 7.27 (2H, d, J 8.6, ArH), 6.86 (2H, d,
J 8.6, ArH), 4.24 (1H, dd, J 10.5, 2.5, OCHAr), 4.10 (1H, dd, J 10.6, 3.9,
OCHH), 3.75 (3H, s, OCH3), 3.57 (1H, dt, J 10.6, 2.7, OCHH), 1.95e1.90
(1H, m, CH2), 1.80e1.73 (1H, m, CH2), 1.70e1.50 (4H, m, CH2);
dC (75 MHz, CDCl3) 158.9, 135.6, 127.6, 127.2, 113.7, 113.2, 79.8,
69.1, 55.3, 33.9, 25.9, 24.1. Data were consistent with those
reported.12b
3.8. Synthesis of 1-cyclohexylpentane-1,5-diol 5h
The procedure described for 5a was followed utilising methyl-5-
cyclohexyl-5-oxopentanoate (0.600 g, 2.83 mmol, 1.0 equiv) and
LiAlH4 (2.0 M) in anhydrous THF (5.30 mL, 10.6 mmol, 3.7 equiv`).
Product 5h (0.461 g, 87.6%) was isolated as white crystals. Mp
39e41 ꢁC; MS: m/z (ESIþ): 209.1 ([MþNa]þ); HRMS: calcd for
C11H22NaO2: 209.1503 ([MþNa]þ). Found 209.1512 ([MþNa]þ); nmax
3277 (br), 2914 (s), 1444 (m) and 1050 (s) cmꢀ1
; dH (300 MHz,
CDCl3) 3.65 (2H, dd, J 6.2, 6.2, CH2OH), 3.38e3.28 (1H, m, CHOH),
1.83e0.91 (19H, m, alkyl-CHþOH); dC (75 MHz, CDCl3) 75.5, 62.1,
43.1, 33.0, 32.0, 28.6, 27.2, 25.9, 25.7, 25.6, 21.5.
3.9.6. 2-(4-Methoxyphenyl)tetrahydrooxepine4f. A mixture of product
4f and the dimer 4fD were formed, in the ratios given in Table 1
and the Supplementary data. Product 4f was a colourless oil. MS:
m/z (ESIþ): 229.4 ([MþNa]þ); HRMS: calcd for C13H18NaO2: 229.1199
([MþNa]þ). Found 229.1199 ([MþNa]þ); nmax 2936 (b), 1612 (m), 1511
3.9. Cyclisation of diols 5aeh, to cyclic ethers 4aeh
(s), 1250 (s) and 816 (s) cmꢀ1
; dH (300 MHz, CDCl3) 7.27 (2H, d, J 8.6,
A Radleys carousel was used to run up for twelve cyclisation
reactions under the same conditions; each set of monosubstituted
diols was run together. For each monosubstituted diol, four re-
actions were run; one blank reaction and one reaction for each of
ArH), 6.86 (2H, d, J 8.6, ArH), 4.55 (1H, dd, J 9.2, 3.7, OCHAr), 3.90
(1H, m, OCHH), 3.80 (3H, s, OCH3), 3.70 (1H, m, OCHH), 2.10e1.20 (8H,
m, alkyl-H). Data were consistent with those reported.20 Dimer
4fD was isolated as a white crystalline solid. MS: m/z (ESIþ): 435.2