The Journal of Organic Chemistry
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homoallylic alcohol. GC conditions: 80 °C isothermal, tR for the (S)-
alcohol = 34.40 min, and tR for the (R)-alcohol = 37.73 min.
2-Phenylpent-4-yn-2-ol, 7 (Table 2, Entry 6).39 Following the
general procedure above, 7 was isolated as a clear, colorless oil (0.555
g, 77% yield). 1H NMR (500 MHz, CDCl3): δ = 1.65 (s, 3H), 2.06 (t,
J = 2.5 Hz, 1H), 2.70 (dd, J = 2.5, 14.0 Hz, 1H), 2.77 (dd, J = 2.5, 14.0
Hz, 1H), 7.28 (t, J = 7.5 Hz, 1H), 7.37 (t, J = 7.0 Hz, 2H), 7.49 (t, J =
7.5 Hz, 2H); 13C NMR (125 MHz, CDCl3): δ = 29.1, 34.5, 72.4, 73.1,
80.3, 124.6, 127.0, 128.2, 145.4. Enantiomeric excess was determined
to be 36% by chiral HPLC analysis. HPLC conditions: 98:2
hexanes/iPrOH, 0.5 mL/min, λ = 251 nm, tR for the (S)-alcohol =
28.96 min, and tR for the (R)-alcohol = 35.66 min.
1,1,1-Trifluoro-2-phenylpent-4-yn-2-ol, 13 (Table 2, Entry
7).20 Following the general procedure above, 13 was isolated as a
yellow oil (0.684 g, 71% yield). 1H NMR (500 MHz, CDCl3): δ = 2.07
(t, J = 2.5 Hz, 1H), 3.11 (d, J = 2.5 Hz, 1H), 3.13 (d, J = 3.0 Hz, 1H),
7.41−7.43 (m, 3H), 7.59 (d, J = 7.5 Hz, 2H). 13C NMR (125 MHz,
CDCl3): δ = 27.4, 73.5, 82.2, 85.4, 126.4, 128.4, 129.0, 136.2, 139.4.
Enantiomeric excess was determined to be 12% by chiral HPLC
analysis of the homoallylic alcohol. HPLC conditions: 95:5
hexanes/iPrOH, 0.5 mL/min, λ = 231 nm, tR for the (R)-alcohol =
54.99 min, and tR for the (S)-alcohol = 57.74 min.
1H), 2.09 (s, 3H), 2.36 (t, J = 8.0, 15.0 Hz, 2H), 2.40−2.42 (m, 2H),
2.63-.64 (m, 1H), 4.74 (d, J = 1.5 Hz, 1H), 4.80 (d, J = 1.5 Hz, 1H),
9.65 (s, 1H). 13C NMR (125 MHz, CDCl3): δ = 18.4, 26.4, 30.0, 40.8,
40.9, 47.5, 115.4, 145.2, 201.9, 208.4.
(5S)-7-Hydroxy-5-(prop-1-en-2-yl)dec-9-en-2-one, 18 (Table
3, Entry 3). Following the general procedure above, 18 was isolated as
a yellow oil (0.360 g, 64% yield). 1H NMR (500 MHz, CDCl3) major
diastereromer: δ = 1.57 (s, 3H), 1.70−1.72 (m, 1H), 2.10 (s, 3H),
2.32−2.36 (m, 3H), 2.14−2.22 (m, 4H), 3.65−3.71* (m, 1H), 4.68 (d,
J = 9.5 Hz, 1H), 4.69 (d, J = 13.0 Hz, 1H), 5.03−5.04 (m, 2H), 5.76−
5.84 (m, 1H). 13C NMR (125 MHz, CDCl3): δ = 17.5, 22.7, 27.3,
31.6, 40.7, 41.7, 43.4, 68.5, 113.4, 118.0, 134.9, 146.4, 209.2. dr 95:5
*(via integration of signals at 3.54−3.58 and 3.65−3.71); 90% de.
1-Phenyl-2-methyl-3-buten-1-ol, 15 (Table 3, Entry 4).42
Following the general procedure above, 15 was isolated as a clear,
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colorless oil (0.423 g, 58% yield). H NMR (600 MHz, CDCl3): δ =
1.82 (s, 3H), 2.15 (d, J = 2.5 Hz, 1H), 2.45 (d, J = 7 Hz, 2H), 4.83 (dt,
J = 2, 7 Hz, 1H), 4.88 (s, 1H), 4.94 (s, 1H), 7.28−7.41 (m, 5H). 13C
NMR (125 MHz, CDCl3): δ = 22.4, 48.4, 71.5, 114.1, 125.8, 127.5,
128.4, 142.4, 144.1. Enantiomeric excess was determined to be 98% by
chiral GC analysis of the acetylated homoallylic alcohol. GC
conditions: 115 °C isothermal, tR for the (S)-alcohol = 60.61 min,
and tR for the (R)-alcohol = 61.51 min.
Methyl 4-(2-Hydroxypent-4-yn-2-yl)benzoate, 14 (Table 2,
entry 8).40 Following the general procedure above, 14 was isolated as
4-Methyl-2-phenylpent-4-en-2-ol, 16 (Table 3, Entry 5).42
Following the general procedure above, 16 was isolated as a yellow oil
(0.635 g, 80% yield). 1H NMR (500 MHz, CDCl3): δ = 1.40 (s, 3H),
1.57 (s, 3H), 2.43 (s, 1H, OH), 2.53 (d, J = 13.0 Hz, 1H), 2.63 (dd, J =
2.5, 9.0 Hz, 1H), 4.76 (s, 1H), 4.90 (s, 1H), 7.24 (t, J = 7.0 Hz, 1H)
7.34 (t, J = 8.0 Hz, 2H), 7.46 (d, J = 7.5 Hz, 2H). 13C NMR (125
MHz, CDCl3): δ = 24.1, 30.6, 52.0, 93.9, 115.7, 124.8, 126.5, 128.1,
142.7, 148.0. Enantiomeric excess was determined to be 78% by chiral
GC analysis. GC conditions: 115 °C isothermal, tR for the (S)-alcohol
= 47.97 min, and tR for the (R)-alcohol = 48.95 min.
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a yellow oil (0.980 g. 51% yield). H NMR (500 MHz, CDCl3): δ =
1.65 (s, 3H), 2.06 (t, J = 2.5 Hz, 1H), 2.71 (dd, J = 2.5, 14.0 Hz, 1H),
2.77 (dd, J = 2.5, 14.0 Hz, 1H), 3.91 (s, 3H), 7.56 (d, J = 8.5 Hz, 2H),
8.03 (d, J = 9.0 Hz, 2H). 13C NMR (125 MHz, CDCl3): δ = 25.3, 29.1,
34.5, 52.0, 72.0, 80.6, 124.7, 128.9, 129.5, 134.4, 151.2, 166.8.
Enantiomeric excess was determined to be 4% by chiral HPLC analysis
of the homoallylic alcohol. HPLC conditions: 90:10 hexanes/iPrOH,
0.5 mL/min, λ = 239 nm, tR for the (S)-alcohol = 81.49 min, and tR for
the (R)-alcohol = 86.45 min.
(S)-1-Phenyl-3-buten-1-ol, 2 (Table 3, Entry 1).41 Following
the general procedure above, 2 was isolated a clear, colorless oil (0.660
g, 99% yield). 1H NMR (500 MHz, CDCl3): δ = 2.50−2.57 (m, 2H),
4.76 (dd, J = 5, 7.5 Hz, 1H), 5.15−5.21 (m, 2H), 5.79−5.87 (m, 1H),
7.28−7.40 (m, 5H). 13C NMR (125 MHz, CDCl3): δ = 43.8, 73.3,
118.5, 125.9, 127.6, 128.5, 134.5, 143.9. Enantiomeric excess was
determined to be 93% by chiral GC analysis of the acetylated
homoallylic alcohol. GC conditions: 115 °C isothermal, tR for the (R)-
alcohol = 45.28 min, and tR for the (S)-alcohol = 45.86 min. The
absolute stereochemistry was determined by comparison of elution
order from the GC with known standards; all others were assigned by
analogy.
1,1,1-Trifluoro-4-methyl-2-phenylpent-4-en-2-ol, 19 (Table
3, Entry 6).43 Following the general procedure above, 19 was isolated
as a yellow oil (0.932 g, 90% yield). 1H NMR (500 MHz, CDCl3): δ =
1.54 (s, 3H), 2.49 (d, J = 13.0 Hz, 1H), 2.59 (d, J = 13.5 Hz, 1H), 4.71
(s, 1H), 4.85 (s, 1H), 7.19 (t, J = 7.5 Hz, 1H), 7.29 (t, J = 7.5 Hz, 2H),
7.42 (d, J = 7.5 Hz, 2H). 13C NMR (125 MHz, CDCl3): δ = 30.5, 52.0,
82.3, 115.6, 124.8, 126.5, 128.0, 142.5, 147.9, 157.9. Enantiomeric
excess was determined to be 12% by chiral GC analysis. GC
conditions: 120 °C isothermal, tR for the (R)-alcohol = 23.13 min, and
tR for the (S)-alcohol = 24.13 min.
2,4-Dimethylnon-1-en-4-ol, 20 (Table 3, Entry 7).44 Following
the general procedure above, 20 was isolated as a clear, colorless oil
(0.690 g, 90% yield). 1H NMR (500 MHz, CDCl3): δ = 0.89 (t, J = 7.0
Hz, 3H), 1.26−1.34 (m, 6H), 1.83 (s, 3H), 2.14 (d, J = 7.5 Hz, 1H),
2.19 (d, J = 14.0 Hz, 2H), 2.23 (d, J = 6.0 Hz, 1H), 4.75 (s, 1H), 4.93
(s, 1H). 13C NMR (125 MHz, CDCl3): δ = 14.0, 22.6, 23.7, 25.0, 26.9,
32.4, 42.5, 49.2, 84.2, 114.8, 142.9. Enantiomeric excess was
determined to be 80% by chiral GC analysis of the homoallylic
alcohol. GC conditions: 115 °C isothermal, tR for the (S)-alcohol =
15.63 min, and tR for the (R)-alcohol = 15.99 min.
4-(2-Hydroxy-4-methylpent-4-en-2-yl)benzonitrile, 21
(Table 3, Entry 8).45 Following the general procedure above, 21
was isolated as a yellow oil (0.543 g, 60% yield). 1H NMR (500 MHz,
CDCl3): δ = 1.42 (s, 3H), 1.56 (s, 3H), 2.53 (d, J = 13.0 Hz, 1H), 2.63
(d, J = 13.5 Hz, 1H), 4.74 (s, 1H), 4.92 (s, 1H), 7.57 (d, J = 8.0 Hz,
2H) 7.62 (t, J = 8.5 Hz, 2H). 13C NMR (125 MHz, CDCl3): δ = 24.1,
28.5, 51.6, 73.1, 108.5, 111.5, 118.8, 125.7, 131.9, 141.5, 163.3.
Enantiomeric excess was determined to be 4% by chiral HPLC
analysis. HPLC conditions: 98:2 hexanes/iPrOH, 0.5 mL/min, λ = 234
nm, tR for the (R)-alcohol = 45.56 min, and tR for the (S)-alcohol =
49.81 min.
(S)-2-Phenylpent-4-en-2-ol, 17 (Table 3, Entry 2).41 Following
the general procedure above, 17 was isolated as a yellow oil (0.520 g,
71% yield). 1H NMR (500 MHz, CDCl3): δ = 1.57 (s, 3H), 2.52 (dd, J
= 6, 13.5 Hz, 1H), 2.70 (dd, J = 7.5, 14.0 Hz, 1H), 5.13−5.15 (m, 2H),
5.60−5.69 (m, 1H), 7.27 (d, J = 9.5 Hz, 1H), 7.37 (t, J = 7.5 Hz, 2H),
7.47 (d, J = 8.0 Hz, 2H). 13C NMR (125 MHz, CDCl3): δ = 29.9, 48.4,
69.2, 119.5, 124.8, 126.7, 128.2, 133.7, 144.9. Enantiomeric excess was
determined to be 24% by chiral GC analysis. GC conditions: 120 °C
isothermal, tR for the (R)-alcohol = 29.85 min, and tR for the (S)-
alcohol = 30.13 min. The absolute stereochemistry was determined by
comparison of elution order from the GC with known standards; all
others were assigned by analogy.
(S)-6-Oxo-3-(prop-1-en-2-yl)heptanal (Table 3, Entry 3).20 To
a 100 mL round-bottom flask were added sodium metaperiodate
(NaIO4, 4.278 g, 20 mmol) and DI water (13 mL) followed by
vigorous mixing for 10 min. After the brief period of stirring, THF (27
mL) was added, subsequent dropwise addition of (−)-limonene oxide
(1.64 mL, 10 mmol) occurred, and the reaction was allowed to stir for
24 h, at which point the iodine salts were filtered off. Ether (Et2O, 15
mL) was added to the filtrate and transferred to a separatory funnel,
and the aqueous phase was washed with Et2O (3 × 15 mL). The
organic layers were combined and washed with DI water (1 × 10 mL)
and brine (1 × 10 mL), dried with MgSO4, filtered, and concentrated
Methyl 4-(2-Hydroxy-4-methylpent-4-en-2-yl)benzoate, 22
(Table 3, Entry 9).43 Following the general procedure above, 22 was
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isolated as a yellow oil (0.760 g. 72% yield). H NMR (500 MHz,
CDCl3): δ = 1.38 (s, 3H), 1.55 (s, 3H), 2.51 (d, J = 14.0 Hz, 1H), 2.63
(d, J = 13.5 Hz, 1H), 3.89 (s, 3H), 4.72 (s, 1H), 4.87 (s, 1H), 7.51 (d, J
= 9.0 Hz, 2H), 7.97 (d, J = 8.5 Hz, 2H). 13C NMR (125 MHz,
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in vacuo to yield 7 (1.612 g, 96% yield) as a clear oil. H NMR (500
MHz, CDCl3): δ = 1.60 (s, 3H), 1.65−1.70 (m, 1H), 1.81−1.83 (m,
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dx.doi.org/10.1021/jo300260a | J. Org. Chem. 2012, 77, 4342−4353