K. H. Kim et al. / Tetrahedron Letters 52 (2011) 5605–5609
5609
(1.0 mL) was stirred at room temperature for 12 h under nitrogen atmosphere.
After the usual aqueous workup and column chromatographic purification
process (hexanes/Et2O, 50:1) compound 1e was obtained as colorless oil,
127 mg (90%). Other starting materials 1a–j were prepared similarly,4,7 and the
selected spectroscopic data of unknown compounds 1e–h are as follows.
compounds 3e–h and 6 are as follows.
Compound 3e: 84%; colorless oil; IR (film) 2955, 2929, 2858, 1465, 1254,
1074 cmÀ1 1H NMR (CDCl3, 300 MHz) d 0.01 (s, 3H), 0.03 (s, 3H), 0.70–0.85 (m,
;
12H), 1.09–1.36 (m, 6H), 1.45–1.55 (m, 2H), 2.61–2.68 (m, 1H), 4.81 (d,
J = 3.6 Hz, 1H), 4.85 (d, J = 2.4 Hz, 1H), 5.40 (d, J = 2.4 Hz, 1H), 7.10–7.16 (m,
2H), 7.17–7.23 (m, 1H), 7.31–7.36 (m, 1H); 13C NMR (CDCl3, 75 MHz) d À4.03,
À3.86, 14.10, 18.14, 22.59, 25.92, 26.06, 31.73, 32.30, 53.77, 79.08, 103.58,
120.60, 125.22, 128.22, 128.62, 140.08, 146.12, 150.48; ESIMS m/z 331 [M+H]+.
Anal. Calcd for C21H34OSi: C, 76.30; H, 10.37. Found: C, 76.53; H, 10.16.
Compound 3f: 82%; colorless oil; IR (film) 2955, 2929, 2857, 1463, 1254,
Compound 1e: 90%; colorless oil; IR (film) 2953, 2857, 1723, 1463, 1256 cmÀ1
;
1H NMR (CDCl3, 300 MHz) d À0.29 (s, 3H), 0.02 (s, 3H), 0.77–0.97 (m, 12H),
1.06–1.32 (m, 6H), 1.51–1.62 (m, 1H), 1.71–1.85 (m, 1H), 2.97–3.09 (m, 1H),
3.63 (s, 3H), 5.04 (d, J = 6.6 Hz, 1H), 5.52 (d, J = 0.6 Hz, 1H), 6.23 (s, 1H), 7.02–
7.07 (m, 1H), 7.25 (t, J = 7.5 Hz, 1H), 7.42 (dd, J = 7.8 and 1.2 Hz, 1H), 7.51 (d,
J = 7.5 Hz, 1H); 13C NMR (CDCl3, 75 MHz) d À5.04, À4.89, 14.05, 18.03, 22.49,
25.79, 26.72, 28.83, 31.87, 47.63, 51.64, 75.05, 122.43, 126.78, 127.16, 128.49,
130.02, 132.17, 139.35, 142.65, 167.80; ESIMS m/z 491 [M+Na]+, 493
[M+Na+2]+. Anal. Calcd for C23H37BrO3Si: C, 58.83; H, 7.94. Found: C, 58.98;
H, 8.02.
1108 cmÀ1 1H NMR (CDCl3, 300 MHz) d 0.16 (s, 3H), 0.21 (s, 3H), 0.81–1.00 (m,
;
12H), 1.19–1.50 (m, 6H), 1.65–1.72 (m, 2H), 2.83–2.89 (m, 1H), 4.98 (d,
J = 3.6 Hz, 1H), 5.30 (d, J = 1.8 Hz, 1H), 5.92 (d, J = 2.1 Hz, 1H), 7.44–7.57 (m,
3H), 7.76 (d, J = 8.4 Hz, 1H), 7.87 (d, J = 7.2 Hz, 1H), 8.47 (d, J = 8.4 Hz, 1H); 13C
NMR (CDCl3, 75 MHz) d À3.98, À3.90, 14.11, 18.19, 22.61, 25.93, 26.38, 31.64,
32.28, 55.94, 78.89, 107.89, 122.95, 124.46, 125.54, 126.86, 129.03, 129.35,
129.64, 134.19, 134.80, 145.24, 150.81; ESIMS m/z 381 [M+H]+. Anal. Calcd for
Compound 1f: 90%; colorless oil; IR (film) 2954, 2930, 2857, 1723, 1257,
1076 cmÀ1
;
1H NMR (CDCl3, 300 MHz) d À0.31 (s, 3H), 0.06 (s, 3H), 0.81–0.86
(m, 12H), 1.04–1.26 (m, 6H), 1.59–1.71 (m, 1H), 1.79–1.87 (m, 1H), 3.08–3.15
(m, 1H), 3.55 (s, 3H), 5.38 (d, J = 6.9 Hz, 1H), 5.53 (s, 1H), 6.18 (d, J = 0.9 Hz, 1H),
7.47–7.59 (m, 2H), 7.64 (d, J = 8.4 Hz, 1H), 7.74–7.80 (m, 2H), 8.32 (d, J = 7.5 Hz,
1H); 13C NMR (CDCl3, 75 MHz) d À4.97, À4.85, 14.03, 18.06, 22.51, 25.81,
26.81, 29.14, 31.90, 48.08, 51.57, 76.00, 122.14, 126.33, 126.91, 126.98, 127.06,
127.26, 127.82, 127.97, 131.84, 133.96, 139.23, 140.85, 167.70; ESIMS m/z 541
[M+Na]+, 543 [M+Na+2]+. Anal. Calcd for C27H39BrO3Si: C, 62.41; H, 7.57.
Found: C, 62.65; H, 7.42.
C
25H36OSi: C, 78.89; H, 9.53. Found: C, 78.74; H, 9.49.
Compound 3g: 86%; white solid, mp 48–49 °C; IR (KBr) 2958, 2930, 2857, 1464,
1256, 1106 cmÀ1 1H NMR (CDCl3, 300 MHz) d 0.17 (s, 3H), 0.21 (s, 3H), 0.96 (s,
;
9H), 1.32 (d, J = 6.9 Hz, 3H), 2.75–2.85 (m, 1H), 4.77 (d, J = 5.4 Hz, 1H), 4.96 (d,
J = 2.4 Hz, 1H), 5.47 (d, J = 2.7 Hz, 1H), 7.23–7.29 (m, 2H), 7.30–7.35 (m, 1H),
7.45–7.48 (m, 1H); 13C NMR (CDCl3, 75 MHz) d À4.06, À4.03, 16.26, 18.10,
25.90, 49.12, 81.33, 102.51, 120.50, 124.53, 128.05, 128.71, 139.44, 146.07,
151.39; ESIMS m/z 275 [M+H]+. Anal. Calcd for C17H26OSi: C, 74.39; H, 9.55.
Found: C, 74.71; H, 9.34.
Compound 1g: 88%; colorless oil; IR (film) 2953, 2931, 2857, 1723, 1466,
1259 cmÀ1
;
1H NMR (CDCl3, 300 MHz) d 0.00 (s, 3H), 0.26 (s, 3H), 1.14 (s, 9H),
Compound 3h: 81%; colorless oil; IR (film) 2954, 2930, 2857, 1646, 1468, 1358,
1.33 (d, J = 7.2 Hz, 3H), 3.43–3.51 (m, 1H), 3.99 (s, 3H), 5.41 (d, J = 4.8 Hz, 1H),
5.90 (t, J = 1.2 Hz, 1H), 6.55 (s, 1H), 7.36 (ddd, J = 7.5, 7.5 and 1.8 Hz, 1H), 7.53–
7.58 (m, 1H), 7.75 (dd, J = 8.1 and 1.5 Hz, 1H), 7.80 (d, J = 7.2 Hz, 1H); 13C NMR
1255 cmÀ1 1H NMR (CDCl3, 300 MHz) d 0.16 (s, 3H), 0.18 (s, 3H), 0.95 (s, 9H),
;
2.62–2.71 (m, 1H), 3.12 (dddd, J = 16.2, 7.2, 1.8 and 1.8 Hz, 1H), 5.03 (dd, J = 1.8
and 1.8 Hz, 1H), 5.30 (dd, J = 7.2 and 5.4 Hz, 1H), 5.46 (dd, J = 2.7 and 1.8 Hz,
1H), 7.24–7.29 (m, 2H), 7.30–7.39 (m, 1H), 7.46–7.51 (m, 1H); 13C NMR (CDCl3,
75 MHz) d À4.60, À4.38, 18.25, 25.90, 43.29, 73.67, 103.32, 120.41, 124.85,
128.13, 128.67, 139.73, 146.50, 147.61; ESIMS m/z 261 [M+H]+. Anal. Calcd for
(CDCl3, 75 MHz)
d
À5.20, À4.94, 13.76, 18.07, 25.81, 40.20, 51.65, 74.27,
121.84, 126.55, 126.61, 128.48, 129.91, 132.38, 141.90, 142.57, 167.66; ESIMS
m/z 435 [M+Na]+, 437 [M+Na+2]+. Anal. Calcd for C19H29BrO3Si: C, 55.20; H,
7.07. Found: C, 55.51; H, 7.23.
C
16H24OSi: C, 73.79; H, 9.29. Found: C, 73.83; H, 9.01.
Compound 6: 97%; white solid, mp 106–107 °C; IR (KBr) 3345, 2960, 2859,
1642, 1466, 1327, 1046 cmÀ1 1H NMR (CDCl3, 300 MHz) d 1.35 (d, J = 6.9 Hz,
Compound 1h: 85%; colorless oil; IR (film) 2953, 2931, 2857, 1726, 1631,
1468 cmÀ1
;
1H NMR (CDCl3, 300 MHz) d À0.26 (s, 3H), À0.09 (s, 3H), 0.77 (s,
;
9H), 2.49 (ddd, J = 13.2, 8.1 and 0.9 Hz, 1H), 2.63 (ddd, J = 13.2, 4.5 and 1.2 Hz,
1H), 3.65 (s, 3H), 5.18 (dd, J = 8.1 and 4.5 Hz, 1H), 5.42–5.43 (m, 1H), 6.13 (d,
J = 1.5 Hz, 1H), 6.98–7.03 (m, 1H), 7.18–7.25 (m, 1H), 7.39 (dd, J = 8.1 and
1.2 Hz, 1H), 7.47 (dd, J = 7.8 and 1.8 Hz, 1H); 13C NMR (CDCl3, 75 MHz) d À4.88,
À4.71, 18.37, 26.03, 42.09, 52.03, 72.46, 121.74, 127.63, 128.60, 128.81, 132.47,
136.84, 144.18, 167.79 (one carbon is overlapped); ESIMS m/z 421 [M+Na]+,
423 [M+Na+2]+. Anal. Calcd for C18H27BrO3Si: C, 54.13; H, 6.81. Found: C,
54.19; H, 6.64.
3H), 1.96 (br s, 1H), 2.70–2.81 (m, 1H), 4.75 (s, 1H), 5.01 (d, J = 2.1 Hz, 1H), 5.51
(d, J = 2.7 Hz, 1H), 7.28–7.34 (m, 2H), 7.41–7.52 (m, 2H); 13C NMR (CDCl3,
75 MHz) d 16.56, 49.50, 81.05, 103.25, 120.69, 124.56, 128.65, 128.96, 139.63,
145.24, 151.13; ESIMS m/z 161 [M+H]+. Anal. Calcd for C11H12O: C, 82.46; H,
7.55. Found: C, 82.18; H, 7.43.
11. The use of TBS-protected starting materials was crucial for the effective
reaction. When we use the corresponding acetate derivative instead of 1a, both
5-exo-trig and 6-endo-trig carbopalladation compete, as previously observed.4
In addition, the use alcohol derivatives directly without protection with TBS
Typical procedure for the synthesis of compound 3a: A solution of 1a4 (143 mg,
0.3 mmol), Pd(OAc)2 (3 mg, 5 mol%), PPh3 (8 mg, 10 mol%), triethylamine
(61 mg, 0.6 mmol) and NaI (45 mg, 0.3 mmol) in DMF (1.0 mL) was stirred at
120 °C for 6 h under nitrogen atmosphere. After the usual aqueous workup and
column chromatographic purification process (hexanes/Et2O 50:1) compound
3a was obtained as colorless oil, 89 mg (88%).4 Other compounds 3b–j4,7 were
synthesized similarly, and the selected spectroscopic data of unknown
moiety showed the formation of intractable complex mixtures including
c-
hydroxybutenolide.4,7
12. (a) Basavaiah, D.; Reddy, K. R.; Kumaragurubaran, N. Nat. Protoc. 2007, 2, 2665–
2676; (b) Das, B.; Damodar, K.; Bhunia, N.; Shashikanth, B. Tetrahedron Lett.
2009, 50, 2072–2074.