Y. Yamamoto et al. / Tetrahedron 62 (2006) 4294–4305
4301
(s, 2H), 3.54 (s, 2H), 3.75 (s, 4H), 4.12–4.23 (m, 8H), 7.07
(d, JZ7.5 Hz, 1H), 7.52 (s, 1H), 7.53 (d, JZ7.5 Hz, 1H);
13C NMR (75 MHz, CDCl3): d 13.9, 22.0, 31.9, 34.6, 34.9,
57.5, 61.7, 72.3, 127.4, 131.4, 131.7, 133.8, 135.3,
169.7, 169.8; MS (EI): m/z (%): 532 (42) [MC], 487 (32)
[MCKOEt], 459 (31) [MCKCO2Et], 413 (70) [MCK
HOEt–CO2Et], 385 (50) [MCKH–2CO2Et], 339 (100)
[MCKH–HOEt–2CO2Et]; EA calcd (%) for C27H37BO10
(532.39): C 60.91, H 7.01; found: C 61.11, H 7.25.
72.2, 73.0, 75.0, 122.9, 126.3, 133.0, 138.0, 145.3; MS (EI):
m/z (%): 231 (72) [MCKH], 204 (100) [MCKCO], 145
(49) [MCKOCH2C(CH3)3]; EA calcd (%) for C13H17BO3
(232.08): C 67.28, H 7.38; found: C 67.26, H 7.40.
4.1.2.12. Compound 11b. Mp 101.6–102.0 8C; 1H NMR
(300 MHz, CDCl3): d 1.04 (s, 6H), 3.79 (s, 4H), 5.21 (t, JZ
2.1 Hz, 2H), 5.32 (t, JZ2.1 Hz, 2H), 7.34 (d, JZ7.5 Hz,
1H), 7.36–7.46 (m, 5H), 7.82 (d, JZ7.5 Hz, 1H); 13C NMR
(75 MHz, CDCl3): d 21.9, 31.9, 72.2, 72.9, 75.1, 126.5,
127.4, 127.7, 128.5, 133.9, 136.0, 137.9, 140.1, 146.3; MS
(EI): m/z (%): 308 (89) [MC], 280 (100) [MCKCO]; EA
calcd (%) for C19H21BO3 (308.18): C 74.05, H 6.87; found:
C 74.07, H 6.98.
4.1.2.7. Compound 4ah. Mp 192.6–193.0 8C; IR
(CHCl3) 1673 (quinone) cmK1 1H NMR (300 MHz,
;
CDCl3): d 1.05 (s, 6H), 3.83 (s, 4H), 7.78–7.82 (m, 2H),
8.20 (dd, JZ7.8, 1.2 Hz, 1H), 8.28 (dd, JZ7.8, 0.3 Hz, 1H),
8.30–8.35 (m, 2H), 8.75 (s, 1H); 13C NMR (75 MHz,
CDCl3): d 21.9, 32.0, 72.4, 125.9, 126.93, 127.0, 132.2,
132.7, 133.4, 133.4, 133.7, 133.9, 134.5, 139.1, 183.0,
183.2; MS (EI): m/z (%): 320 (100) [MC], 280 (85) [MCK
C3H4], 235 (95) [MCKCH2C(Me)2CHO]; EA calcd (%)
for C19H17BO4 (320.15): C 71.28, H 5.35; found: C 71.05,
H 5.53.
4.1.2.13. Compound 11c. Mp 86.3–86.5 8C; ca. 1:1
mixture of ortho and meta isomers: H NMR (300 MHz,
1
CDCl3): ortho-11b d 0.95 (t, JZ7.2 Hz, 3H), 1.05 (s, 6H),
1.31–1.45 (m, 2H), 1.51–1.67 (m, 2H), 2.87 (t, JZ7.8 Hz,
2H), 3.77 (s, 3H), 5.07–5.09 (m, 2H), 5.20–5.23 (m, 2H),
7.08 (d, JZ7.8 Hz, 1H), 7.15 (d, JZ7.8 Hz, 1H); meta-11b
d 0.94 (t, JZ7.2 Hz, 3H), 1.02 (s, 6H), 1.31–1.45 (m, 2H),
1.51–1.67 (m, 2H), 2.64 (t, JZ7.8 Hz, 2H), 3.76 (s, 3H),
5.07–5.09 (m, 2H), 5.20–5.23 (m, 2H), 7.12 (s, 1H), 7.54
(s, 1H); 13C NMR (75 MHz, CDCl3): d 14.04 and 14.07,
21.90 and 21.91, 22.5 and 22.8, 31.6 and 31.8, 34.1 and
35.9, 35.47 and 35.51, 72.0 and 72.1, 72.9 and 73.1, 74.9
and 75.1, 121.8 and 122.9, 128.3 and 133.2, 135.2 and
138.3, 141.0 and 142.7, 145.3 and 148.1; MS (EI): m/z (%):
286 (31) [MC], 243 (25) [MCKCH2CH2CH3]; EA calcd
(%) for C17H25BO3 (288.19): C 70.85, H 8.74; found: C
70.85, H 8.73.
4.1.2.8. Compound 4ba. Mp 38.0–40.8 8C; IR (neat)
1738 (CO2Me) cmK1; 1H NMR (300 MHz, CDCl3): d 0.91
(t, JZ7.2 Hz, 3H), 1.03 (s, 6H), 1.35 (sext, JZ7.2 Hz, 2H),
1.46–1.57 (m, 2H), 2.81 (t, JZ7.8 Hz, 2H), 3.55 (s, 4H),
3.73 (s, 6H), 3.75 (s, 4H), 6.99 (s, 1H), 7.55 (s, 1H); 13C
NMR (75 MHz, CDCl3): d 14.1, 21.9, 22.9, 31.6, 35.5, 35.7,
40.2, 40.7, 52.9, 60.4, 72.2, 125.0, 130.3, 136.1, 141.9,
148.2, 172.0; MS (EI): m/z (%): 402 (44) [MC], 342 (100)
[MCKH–CO2Me], 299 (24) [MCKH–CO2Me–Pr]; EA
calcd (%) for C22H31BO6$H2O (420.30): C 62.87, H 7.91;
found: C 62.79, H 7.98.
4.1.2.14. Compound 11d. Mp 65.8–66.2 8C; ca. 7:3
mixture of ortho and meta isomers: IR (neat) 1720
4.1.2.9. Compound 4ai. Mp 160.1–160.5 8C; IR
(CHCl3) 1732 (CO2Me) cmK1 1H NMR (300 MHz,
;
1
(CO2Me) cmK1; H NMR (300 MHz, CDCl3): ortho-11c d
CDCl3): meta-4ai d 1.01 (s, 6H), 2.26 (s, 3H), 3.54 (s,
2H), 3.60 (s, 2H), 3.74 (s, 6H), 3.75 (s, 4H), 7.43 (s, 1H),
7.47 (s, 1H); ortho-4ai d 1.02 (s, 6H), 2.42 (s, 3H), 3.55 (s,
2H), 3.60 (s, 2H), 3.74 (s, 6H), 3.76 (s, 4H), 7.01 (d, JZ
7.5 Hz, 1H), 7.57 (d, JZ7.5 Hz, 1H); 13C NMR (75 MHz,
CDCl3): meta-4ai d 18.9, 21.9, 31.9, 39.6, 40.6, 52.9, 59.8,
72.2, 120.5, 126.8, 133.3, 138.8, 141.5, 172.0; ortho-4ai d
18.5, 21.9, 31.6, 39.9, 41.0, 52.9, 59.5, 72.2, 132.7, 134.0,
138.7, 139.5, 141.4, 172.1; MS (EI): m/z (%): 360 (31)
[MC], 300 (100) [MCKH–CO2Me]; EA calcd (%) for
C19H25BO6 (360.21): C 63.35, H 7.00; found: C 63.27,
H 7.01.
1.04 (s, 6H), 3.38 (s, 3H), 3.75 (s, 4H), 4.65 (s, 2H), 5.06 (s,
2H), 5.19 (t, JZ1.8 Hz, 2H), 7.19 (d, JZ7.5 Hz, 1H), 7.25
(d, JZ7.5 Hz, 1H); meta-11c d 1.01 (s, 6H), 3.38 (s, 3H),
3.75 (s, 4H), 4.46 (s, 2H), 5.08 (s, 2H), 5.22 (t, JZ1.8 Hz,
2H), 7.29 (s, 1H), 7.65 (s, 1H); 13C NMR (75 MHz, CDCl3):
ortho-11c d 21.9, 31.7, 58.1, 72.1, 73.0, 74.3, 74.8, 121.7,
126.7, 137.3, 142.5, 145.1; meta-11c d 21.9, 31.9, 58.1,
72.2, 72.9, 74.6, 74.9, 122.5, 132.9, 136.4, 138.6, 145.0; MS
(EI): m/z (%): 279 (100) [MC], 248 (28) [MCKHOMe]; EA
calcd (%) for C15H21BO4 (276.14): C 65.24, H 7.67; found:
C 65.35, H 7.56.
4.1.2.15. Compound 13a. Oil; ca. 1:1 mixture of ortho
and meta isomers: 1H NMR (300 MHz, CDCl3): ortho-13a d
0.92 (t, JZ7.2 Hz, 3H), 1.36 (sept, JZ7.2 Hz, 2H), 1.50–
1.65 (m, 2H), 2.92 (t, JZ7.8 Hz, 2H), 3.88 (s, 3H), 5.08 (s,
2H), 5.24 (t, JZ1.8 Hz, 2H), 7.17 (d, JZ7.8 Hz, 1H), 7.24
(d, JZ7.8 Hz, 1H); meta-13a d 0.92 (t, JZ7.2 Hz, 3H), 1.02
(s, 6H), 1.36 (sept, JZ7.2 Hz, 2H), 1.50–1.65 (m, 2H), 2.66
(t, JZ7.8 Hz, 2H), 3.90 (s, 3H), 5.09 (s, 2H), 5.34 (t, JZ
1.8 Hz, 2H), 7.23 (s, 1H), 7.74 (s, 1H); 13C NMR (75 MHz,
CDCl3): d 13.98 and 14.03, 22.3 and 22.8, 33.7 and 35.3,
34.0 and 34.3, 51.7 and 52.0, 72.9 and 73.1, 74.8 and
74.9, 123.7 and 125.3, 123.9 and 124.0, 128.7 and 130.3,
137.5 and 138.9, 140.6 and 141.2, 142.7 and 143.6,
166.4 and 167.4; MS (EI): m/z (%): 234 (100) [MC],
217 (93) [MCKH–Me], 206 (42) [MCKCO], 189 (64)
4.1.2.10. Compound 4aj. Mp 116.1–116.2 8C; IR (neat)
1721 (CO2Me) cmK1; 1H NMR (300 MHz, CDCl3): d 1.02
(s, 6H), 2.21 (s, 3H), 2.39 (s, 3H), 3.54 (s, 2H), 3.56 (s, 2H),
3.75 (s, 6H), 3.76 (s, 4H), 7.39 (s, 1H); 13C NMR (75 MHz,
CDCl3): d 18.3, 18.6, 21.9, 31.7, 39.9, 40.2, 53.0, 59.3, 72.2,
129.6, 134.7, 136.6, 138.6, 140.4, 172.2; MS (EI): m/z (%):
374 (45) [MC], 314 (100) [MCKH–CO2Me]; EA calcd (%)
for C20H27BO6 (374.24): C 64.19, H 7.27; found: C 64.13,
H 7.54.
1
4.1.2.11. Compound 11a. Mp 95.3–95.4 8C; H NMR
(300 MHz, CDCl3): d 1.02 (s, 6H), 3.76 (s, 4H), 5.09–5.11
(m, 2H), 5.25 (t, JZ2.1 Hz, 2H), 7.23–7.32 (m, 2H), 7.69–
7.72 (m, 1H); 13C NMR (75 MHz, CDCl3): d 21.9, 31.9,