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T. Takahashi et al. / Journal of Fluorine Chemistry 127 (2006) 760–768
1
H), 3.02–3.11 (m, 1H, 3-H), 3.16–3.24 (m, 1H, 3-H), 4.76 and
4.81 (each ddd, 1H, J = 4.3, 11.1, 11.1 Hz, 10aq-H), 7.18–7.42
(m, 4H, Ph-H); 13C NMR (75.46 MHz) d 16.3 and 16.4 (each s,
CH3, 90-C), 20.8 and 21.1 (each s, CH3, 80-C), 22.2 and 22.3
(each s, CH3, 100-C), 23.4 and 23.6 (each s, CH2, 30-C), 26.2
and 26.5 (each s, CH, 70-C), 30.5 (s, CH2, 3-C), 31.6 and 31.7
(each s, CH, 50-C), 34.3 and 34.4 (each s, CH2, 40-C), 36.4 and
36.6 (each d, J = 23.2 Hz, CH2, 2-C), 40.5 and 40.9 (each s,
CH2, 60-C), 47.0 and 47.2 (each s, CH, 20-C), 76.1 and 76.2
(each s, CH, 10-C), 102.0 and 102.1 (each d, J = 195.3,
200.2 Hz, C, 1-C), 124.1 (s, CH, 7-C), 125.1 (s, CH, 4-C),
127.1 (d, J = 12.2 Hz, CH, 6-C), 130.4 (d, J = 2.4 Hz, CH, 5-
C), 139.6 (d, J = 20.8 Hz, C, 7a-C), 144.8 and 144.9 (each d,
J = 4.9 Hz, C, 3a-C), 170.3 and 170.2 (each d, J = 33.0 Hz, C,
COO); 19F NMR (254 MHz) d ꢀ139.83 (t, J = 19.0 Hz)
and ꢀ138.80 (t, J = 21.7 Hz) (Dd = 1.03); MS m/z: 318 (M+),
298 ([M ꢀ HF]+), 135 ([M ꢀ COOR*]+), 115 (indenyl
cation); HRMS calcd. for C20H27O2F (M+): 318.1995, found:
318.1976.
(CH), 1745 cmꢀ1 (C O); H NMR (500 MHz) d 0.75 (dddd,
1H, J = 3.0, 12.4, 12.4, 12.4 Hz, 40aq-H), 0.77 (ddd, 1H,
J = 12.4, 12.4, 12.4 Hz, 60aq-H), 0.80 (d, 3H, J = 6.4 Hz, 100-
H), 1.03 (dddd, 1H, J = 3.4, 12.8, 12.8, 13.2 Hz, 30aq-H), 1.25
(s, 3H, 90-H), 1.38 (s, 3H, 80-H), 1.41 (m, 1H, 50aq-H), 1.50
(dddd, 1H, J = 3.4, 3.4, 3.4, 13.7 Hz, 30eq-H), 1.54 (ddddd, 1H,
J = 3.0, 3.4, 3.8, 3.8, 12.8 Hz, 40eq-H), 1.73 (dddddd, 1H,
J = 1.7, 2.1, 2.1, 2.1, 2.1, 12.0 Hz, 60eq-H), 1.99 (ddd, 1H,
J = 3.4, 10.7, 12.4 Hz, 20aq-H), 2.14–2.21 (m, 2H, 2-H), 2.87
(m, 1H, 3-H), 3.07 (m, 1H, 3-H), 5.01 (ddd, 1H, J = 4.3, 10.7,
10.7 Hz, 10aq-H), 7.14–7.17 (m, 1H, p0-H), 7.25 (t, 1H,
J = 7.7 Hz, 6-H), 7.27–7.29 (m, 5H, 4, o0-, m0-H), 7.34–7.37 (m,
13
2H, 5, 7-H); C NMR (75.46 MHz) d 22.0 (s, CH3, 100-C),
26.6(s, CH3, 90-C), 27.2 (s, CH2, 30-C), 27.8 (s, CH3, 80-C), 30.4
(s, CH2, 3-C), 31.5 (s, CH, 50-C), 34.5 (s, CH2, 40-C), 35.5 (d,
J = 23.2 Hz, CH2, 2-C), 40.3 (s, C, 70-C), 41.3 (s, CH2, 60-C),
50.0 (s, CH, 20-C), 76.8 (s, CH, 10-C), 102.0 (d, J = 189.2 Hz, C,
1-C), 124.2 (s, CH, 7-C), 125.1 (s, CH, 4-C), 125.4 (s, CH, p0-
C), 125.6 (s, CH, o0- or m0-C), 127.0 (d, J = 2.4 Hz, CH, 6-C),
128.2 (s, CH, o0- or m0-C), 130.3 (d, J = 3.7 Hz, CH, 5-C), 139.5
(d, J = 20.8 Hz, C, 7a-C), 145.1 (d, J = 3.7 Hz, C, 3a-C), 150.9
(s, C, ipso0-C), 169.8 (d, J = 33.0 Hz, C, COO); 19F NMR
(254 MHz) d ꢀ138.77 (t, J = 22.2 Hz); MS m/z: 394 (M+), 374
([M ꢀ HF]+); HRMS calcd. for C26H31O2F (M+): 394.2308,
found: 394.2269.
4.7.9. (ꢀ)-1-Fluoroindan-1-carboxylic acid (ꢀ)-8-
phenylmenthyl ester (5ia)
The product was isolated in 44% yield as a colorless oil.
[a]D ꢀ33.2 (c 2.69, CHCl3); IR (neat) 2954 cmꢀ1 (CH),
27
1
1732 cmꢀ1 (C O); H NMR (500 MHz) d 0.78 (dddd, 1H,
J = 3.4, 12.0, 12.8, 12.8 Hz, 40aq-H), 0.86 (d, 3H, J = 6.4 Hz,
100-H), 0.96 (dddd, 1H, J = 3.4, 12.8, 12.8, 13.2 Hz, 30aq-H),
1.05 (s, 3H, 90-H), 1.08 (ddd, 1H, J = 10.7, 12.0, 12.0 Hz, 60aq-
H), 1.16 (s, 3H, 80-H), 1.37 (dddd, 1H, J = 3.4, 3.4, 3.8,
13.7 Hz, 30eq-H), 1.45 (m, 1H, 50aq-H), 1.53 (ddddd, 1H,
J = 2.1, 3.4, 3.4, 3.8, 12.8 Hz, 40eq-H), 1.92 (ddd, 1H, J = 3.4,
10.7, 12.4 Hz, 20aq-H), 2.01 (dddddd, 1H, J = 1.7, 1.7, 1.7, 2.1,
2.6, 12.0 Hz, 60eq-H), 2.39 (dddd, 1H, J = 5.6, 8.5, 14.1,
23.5 Hz, 2-H), 2.69 (dddd, 1H, J = 5.1, 8.5, 14.1, 17.9 Hz, 2-
H), 3.04 (m, 1H, 3-H), 3.16 (m, 1H, 3-H), 4.87 (ddd, 1H,
J = 4.3, 10.7, 10.7 Hz, 10aq-H), 7.12 (tt, 1H, J = 1.3, 7.3 Hz, p0-
H), 7.15–7.23 (m, 4H, Ph0-H), 7.26 (t, 1H, J = 7.7 Hz, 6-H),
7.29 (d, 1H, J = 6.8 Hz, 4-H), 7.35 (tt, 1H, J = 1.3, 7.7 Hz, 5-
H), 7.43 (d, 1H, J = 7.7 Hz, 7-H); 13C NMR (75.46 MHz) d
22.0 (s, CH3, 100-C), 24.6(s, CH3, 80-C), 27.4 (s, CH2, 30-C),
29.3 (s, CH3, 90-C), 30.5 (s, CH2, 3-C), 31.6 (s, CH, 50-C), 34.7
(s, CH2, 40-C), 36.1 (d, J = 23.2 Hz, CH2, 2-C), 40.3 (s, C, 70-
C), 41.7 (s, CH2, 60-C), 50.7 (s, CH, 20-C), 77.1 (s, CH, 10-C),
102.0 (d, J = 191.7 Hz, C, 1-C), 124.3 (s, CH, 7-C), 125.2 (s,
CH, 4-C), 125.4 (s, CH, p0-C), 125.7 (s, CH, o0- or m0-C), 127.1
(s, CH, 6-C), 128.0 (s, CH, o0- or m0-C), 130.5 (d, J = 3.7 Hz,
CH, 5-C), 139.3 (d, J = 22.0 Hz, C, 7a-C), 145.0 (d, J = 3.7 Hz,
C, 3a-C), 150.2 (s, C, ipso0-C), 169.8 (d, J = 31.7 Hz, C, COO);
19F NMR (254 MHz) d ꢀ139.13 (t, J = 23.1 Hz); MS m/z: 394
(M+), 374 ([M ꢀ HF]+), 135 ([M ꢀ COOR*]+), 115 (indenyl
cation); HRMS calcd. for C26H31O2F (M+): 394.2308, found:
394.2266.
4.8. General procedure for condensation reaction
of a-methoxy-a-(trifluoromethyl)phenylacetyl chloride with
a secondary alcohol
(R)-or (S)-MTPA chloride (79.2 mmol, 15 mL) was added to
a solution of pyridine (13 mL) and a secondary alcohol
(95 mmol) in dry CH2Cl2 (1 mL) under nitrogen atmosphere
and stirred for 1–2 days. The solvent was evaporated and the
residue was purified by PLC (hexane/AcOEt = 6:1) to give a-
methoxy-a-(trifluoromethyl)-phenylacetic acid ester of a
secondary alcohol (6).
4.8.1. (S)-a-Methoxy-a-(trifluoromethyl)phenylacetic acid
(R)-2-pentyl ester (6b(SR))
The product was isolated in 41% yield as a colorless
oil. [a]D ꢀ62 (c 0.48, CHCl3); IR (neat) 2962 cmꢀ1 (CH),
26
1745 cmꢀ1 (C O), 1268 cmꢀ1 (C–O), 1170 cmꢀ1 (C–O); H
1
NMR (500 MHz) d 0.86 (t, 3H, J = 7.3 Hz, 50-H), 1.17–1.31
(m, 2H, 40-H), 1.34 (d, 3H, J = 6.4 Hz, 10-H), 1.48 (dddd,
1H, J = 5.1, 6.4, 9.8, 14.1 Hz, 30-H), 1.63 (dddd, 1H, J = 5.1,
7.7, 9.8, 14.1 Hz, 30-H), 3.57 (q, 3H, J = 1.3 Hz, OCH3), 5.17
(qdd, 1H, J = 6.4, 5.1, 7.7 Hz, 20-H), 7.39–7.41 (m, 3H,
Ph-H), 7.53–7.55 (m, 2H, Ph-H); 13C NMR (75.46 MHz) d 14.0
(s, CH3, 50-C), 18.6 (s, CH2, 40-C), 20.1 (s, CH3, 10-C),
37.9 (s, CH2, 30-C), 55.6 (s, CH3, OCH3), 74.0 (s, CH, 20-C),
84.6 (q, J = 28.1 Hz, C, 2-C), 123.5 (q, J = 286.9 Hz, C,
CF3), 127.4, 128.4 (s, CH, o-, m-C), 129.6 (s, CH, p-C), 132.7
(s, C, ipso-C), 166.1 (s, C, COO); 19F NMR (254 MHz) d
ꢀ72.01 (s); MS m/z: 303 ([M ꢀ 1]+), 189 ([M ꢀ COOR*]+);
HRMS calcd. for C15H19O3F3 (M+): 304.1286, found:
304.1261.
4.7.10. (+)-1-Fluoroindan-1-carboxylic acid (ꢀ)-8-
phenylmenthyl ester (5ib)
The product was isolated in 48% yield as a colorless solid.
m.p. 88 8C; [a]D27 +1.0 (c 1.13, CHCl3); IR (neat) 2957 cmꢀ1