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A. Roy et al. / Tetrahedron Letters 48 (2007) 6933–6936
H, 8.39%. Found: C, 74.93; H, 8.38%. For 11: IR (neat)
max 1781 cmÀ1; 1H NMR (300 MHz, CDCl3) d 1.30, 1.32
1H), 5.49 (d, J = 12.0 Hz,1H), 5.96–6.03 (m, 1H), 6.53 (s,
m
1H), 6.88 (s, 1H); 13C NMR (75 MHz, CDCl3) d 15.9,
23.4, 24.8, 25.4, 40.3, 55.8, 72.5, 87.3, 106.3, 110.3, 123.4,
124.1, 125.81, 125.86, 134.0, 137.7. Anal. Calcd for
C16H22O3: C, 73.25; H, 8.45%. Found: C, 73.24; H,
(2d, J = 6.9 Hz, 3H), 2.18 (s, 3H), 2.42–2.51 (m, 1H),
2.62–2.68 (m, 1H), 3.78 (s, 3H), 3.91 (m, 1H), 4.31 (dd,
J = 15.7, 8.5 Hz, 1H), 4.46–4.53 (m, 1H), 4.79 (t,
J = 7.8 Hz, 1H), 4.98–5.11 (m, 2H), 5.96–6.05 (m, 1H),
6.63, 6.64 (2s, 1H), 6.88, 6.89 (2s, 1H); 13C NMR
(75 MHz, CDCl3) d 16.1, 19.76 (19.81), 30.2, 35.72
(35.79), 55.92 (55.93), 65.33 (65.39), 74.43 (74.49), 109.8
(110.0), 113.1 (113.3), 118.1 (118.2), 125.32 (125.34), 133.2
(133.6), 142.6 (143.0), 148.3 (148.4), 153.37 (153.39), 174.1.
Anal. Calcd for C16H20O4: C, 69.54; H, 7.30%. Found: C,
8.46%. For 26: IR (neat) mmax 1750 cmÀ1 1H NMR
;
(300 MHz, CDCl3) d 1.40, 1.48 (2d, J = 7.4 Hz, 3H), 2.23
(s, 3H), 3.35 (m, 1/2H), 3.82, 3.85 (2s, 3H), 4.06 (br, 1/2H),
4.98–5.05 (m, 3H), 5.50–5.54 (m, 1/2H), 5.64 (dd, J = 11.8,
1.2 Hz, 1/2H), 5.78–5.80 (m, 1/2H), 5.96–6.09 (m, 1/2H),
6.62, 6.66 (2s, 1H), 6.98, 7.0 (2s, 1H), 7.33–7.46 (m, 5H);
13C NMR (75 MHz, CDCl3) d 16.3, 19.2 (22.9), 33.2
(39.5), 52.8 (52.9), 70.8 (70.9), 79.2 (79.4), 109.3, 111.7,
116.5 124.3 (124.6), 124.7 (125.1), 126.2 (126.7), 127.6
(127.6), 128.2 (128.9), 135.5, 136.8 (137.8), 137.9 (137.9),
138.7, 149.1(149.6), 153.9 (154.0), 170.2 (170.4); HRMS
(ES+ve) calcd for C21H22O4Na [M+Na]+ 361.1416, found
69.56; H, 7.28%. For 14: IR (neat) mmax 1754 cmÀ1 1H
;
NMR (300 MHz, CDCl3) d 1.32, 1.35 (2d, J = 7.2 Hz,
3H), 2.15 (s, 3H), 3.77 (s, 6H), 4.01–405 (m, 1H), 5.02–5.13
(m, 3H), 5.38 (d, J = 10.5 Hz, 1H), 5.58 (d, J = 17.4 Hz,
1H), 6.01–6.11 (m, 2H), 6.59 (s, 1H), 6.64, 6.65 (2s, 1H);
13C NMR (75 MHz, CDCl3) d 16.5, 19.92 (19.96), 35.90
(35.96), 52.9, 56.24 (56.25), 79.4 (79.6), 110.4 (110.5),
113.36 (113.39), 116.99 (117.16), 119.3 (119.4), 125.2,
132.7 (132.8), 133.5 (133.7), 143.1 (143.2), 148.49 (148.50),
153.2, 171.0. Anal. Calcd for C17H22O4: C, 70.32; H,
7.64%. Found: C, 70.30; H, 7.65%. For 15a: IR (neat) mmax
1
361.1414. For 27: H NMR (300 MHz, CDCl3) d 1.31 (s,
3H), 1.33 (s, 3H), 1.45 (d, J = 7.0 Hz, 3H), 2.22 (s, 3H),
2.75 (br s, 1H), 3.19 (m, 1H), 4.08 (br s, 1H), 5.02 (s, 2H),
5.50 (d, J = 11.7 Hz, 1H), 5.96–6.03 (m, 1H), 6.62 (s, 1H),
6.87 (s, 1H), 7.32–7.45 (m, 5H); 13C NMR (75 MHz,
CDCl3) d 16.3, 23.7, 25.1, 25.7, 40.5, 70.9, 72.8, 87.5,
112.3, 124.5, 126.0, 126.7, 127.6, 128.2, 128.9, 134.3, 137.9,
138.0, 150.6, 153.7; HRMS (ES+ve) calcd for
C22H26O3Na [M+Na]+ 361.1779, found 361.1784. For 1:
1H NMR (300 MHz, CDCl3) d 1.30 (s, 3H), 1.32 (s, 3H),
1.43 (d, J = 7.4 Hz, 3H), 2.19 (s, 3H), 2.73 (br s, 1H), 3.15
(m, 1H), 4.06 (br s, 1H), 4.51 (s, 1H), 5.47–5.51 (m, 1H),
5.94–6.01 (m, 1H), 6.51 (s, 1H), 6.81 (s, 1H); 13C NMR
(75 MHz, CDCl3) d 15.4, 23.3, 24.8, 25.4,29.8, 39.8, 72.4,
87.4, 114.9, 122.7, 124.1, 125.7, 133.9, 138.3, 150.0; HRMS
(ES+ve) calcd for C15H20O3Na [M+Na]+ 271.1311, found
271.1317.
1750 cmÀ1 1H NMR (300 MHz, CDCl3) d 1.48 (d,
;
J = 7.2 Hz, 3H), 2.15 (s, 3H), 3.35 (m, 1H), 3.79 (s, 3H),
3.84 (s, 3H), 4.95 (br s, 1H), 5.63 (dd, J = 11.6, 0.9 Hz,
1H), 5.99–6.06 (m, 1H), 6.53 (s, 1H), 6.94 (s, 1H); 13C
NMR (75 MHz, CDCl3) d 15.9, 22.7, 39.4, 52.7, 55.8, 78.9,
109.8, 124.5, 124.7, 125.8, 135.2, 137.6, 149.0, 154.5, 170.2.
Anal. Calcd for C15H18O4: C, 68.68; H, 6.92%. Found: C,
68.70; H, 6.91%. For 15b: IR (neat) mmax 1748 cmÀ1;1H
NMR (300 MHz, CDCl3) d 1.43 (d, J = 7.5 Hz, 3H), 2.17
(s, 3H), 3.81 (s, 3H), 3.82 (s, 3H), 4.05 (br s, 1H), 4.98–5.00
(m, 1H), 5.48–5.53 (m, 1H), 5.78–5.84 (m, 1H), 6.58 (s,
1H), 6.96 (s, 1H); 13C NMR (75 MHz, CDCl3) d 15.8,
18.9, 32.9, 52.6, 55.8, 79.1, 107.2, 124.0, 124.4, 124.7,
136.5, 138.4, 148.5, 154.4, 169.9. Anal. Calcd for
C15H18O4: C, 68.68; H, 6.92%. Found: C, 68.67; H,
6.90%. For 17: 1H NMR (300 MHz, CDCl3) d 1.30 (s,
3H), 1.32 (s, 3H), 1.45 (d, J = 7.2 Hz, 3H), 2.16 (s, 3H),
2.76 (br s, 1H), 3.18–3.23 (m, 1H), 3.79 (s, 1H), 4.06 (br s,
8. Grieco, P. A.; Noguez, J. A.; Masaki, Y. Tetrahedron Lett.
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10. After this work was completed, we came to know of a
synthesis of 1: Zhang, J.; Wang, X.; Wang, W.; Quan, W.;
She, X.; Pan, X. Tetrahedron 2007, 63, 6990–6995.