992
E. Alvarez-Manzaneda et al. / Tetrahedron Letters 48 (2007) 989–992
1
new compounds were fully characterized spectroscopically
Compound 20: H NMR (CDCl
3
, 300 MHz) d: 1.21 (3H,
and had satisfactory high resolution mass spectroscopy
d, J = 6.9 Hz), 1.22 (3H, d, J = 6.9 Hz), 1.27 (3H, s), 1.34
(3H, s), 2.26 (1H, br d, J = 9.1 Hz), 2.33 (1H, m), 2.34
(3H, s), 2.72 (2H, m), 2.99 (1H, h, J = 6.9 Hz), 3.65 (3H,
data. Selected data:
1
Compound 11: H NMR (CDCl
3
, 300 MHz) d: 0.74 (3H,
1
3
s), 0.99 (3H, d, J = 6.8 Hz), 1.03 (3H, d, J = 6.8 Hz), 1.18
3H, s), 2.25 (1H, br d, J = 12.4 Hz), 2.38 (1H, h,
J = 6.8 Hz), 3.56 (3H, s), 4.20 (1H, t, J = 2.9 Hz), 5.45
3
s), 6.99 (1H, s), 7.99 (1H, s). C NMR (CDCl , 75 MHz)
(
d: 37.0 (C-1), 18.1 (C-2), 37.7 (C-3), 46.7 (C-4), 43.6 (C-5),
36.4 (C-6), 197.4 (C-7), 138.7 (C-8), 152.7 (C-9), 37.4, (C-
10), 117.6 (C-11), 154.3 (C-12), 128.9 (C-13), 126.6 (C-14),
27.3 (C-15), 22.7 (C-16), 22.8 (C-17), 177.7 (C-18), 23.6 (C-
19), 16.4 (C-20), 169.1 (OCOCH ) 21.0 (OCOCH ), 52.2
1
3
(
(
(
3
1H, m), 5.77 (1H, s). C NMR (CDCl , 75 MHz) d: 38.1
C-1), 18.1 (C-2), 37.2 (C-3), 46.6 (C-4), 45.1 (C-5), 25.9
C-6), 124.3 (C-7), 134.5 (C-8), 43.6 (C-9), 34.1 (C-10),
3
3
2
(
1
6.0 (C-11), 66.4 (C-12), 144.1 (C-13), 125.6 (C-14), 32.6
C-15), 21.7 (C-16), 22.4 (C-17), 178.9 (C-18), 16.9 (C-19),
4.4 (C-20), 51.9 (COOCH ).
(COOCH
3
).
1
Compound 22: H NMR (CDCl , 300 MHz) d: 0.26 (3H,
3
3
s), 0.28 (3h, 3H), 1.01 (9H, s), 1.19 (3H, d, J = 6.9 Hz),
1.20 (3H, d, J = 6.9 Hz), 1.24 (3H, s), 1.32 (3H, s), 2.19
(1H, br d, J = 12.8 Hz), 2.68 (2H, m), 3.15 (1H, h,
J = 6.9 Hz), 3.64 (3H, s), 6.69 (1H, s), 7.88 (1H, s).
NMR (CDCl , 75 MHz) d: 37.2 (C-1), 18.3 (C-2), 37.7 (C-
1
Compound 16: H NMR (CDCl , 300 MHz) d: 0.83 (3H,
s), 1.04 (3H, d, J = 6.8 Hz), 1.12 (3H, d, J = 6.8 Hz), 1.25
3
1
3
(
3H, s), 2.42 (1H, h, J = 6.8 Hz), 2.55 (1H, m), 3.66 (3H,
C
1
3
s), 4.75 (1H, t, J = 2.9 Hz), 5.56 (1H, m), 5.90 (1H, s).
C
3
NMR (CDCl , 75 MHz) d: 37.6 (C-1), 17.7 (C-2), 36.7 (C-
3), 46.8 (C-4), 44.1 (C-5), 36.6 (C-6), 197.2 (C-7), 137.7 (C-
8), 154.9 (C-9), 37.4 (C-10), 112.7 (C-11), 158.5 (C-12),
124.7 (C-13), 126.3 (C-14), 26.6 (C-15), 22.6 (C-16), 22.7
(C-17), 177.9 (C-18), 23.7 (C-19), 16.5 (C-20), ꢀ3.8 (3H,
Me–Si), ꢀ4.0 (3H, Me–Si), 25.8 (Me, t-Bu), 29.8 (C, t-Bu)
3
3), 46.1 (C-4), 44.5 (C-5), 25.6 (C-6), 125.1 (C-7), 133.6 (C-
8), 43.9 (C-9), 33.6 (C-10), 31.5 (C-11), 58.4 (C-12), 141.9
(
1
C-13), 126.5 (C-14), 31.6 (C-15), 21.1 (C-16), 22.2 (C-17),
78.2 (C-18), 16.7 (C-19), 14.4 (C-20), 51.6 (COOCH ).
3
1
Compound 18: H NMR (CDCl
3
, 300 MHz) d: 1.19 (6H,
3
52.2 (COOCH ).
1
d, J = 5.1 Hz), 1.22 (3H, s), 1.26 (3H, s), 2.17 (1H, br d,
3
Compound 23: H NMR (CDCl , 300 MHz) d: 1.20 (6H,
J = 9.3 Hz), 2.20 (1H, br d, J = 8.1 Hz), 2.80 (2H, m), 3.13
d, J = 6.9 Hz), 1.27 (3H, s), 1.34 (3H, s), 1.60–1.90 (5h, m),
(
1H, h, J = 5.1 Hz), 3.66 (3H, s), 6.63 (1H, s), 6.81 (1H, s).
3
2.33 (2H, m), 2.70 (2H, m), 3.25 (1H, h, J = 6.9 Hz), 3.64
(3H, s), 3.93 (3H, s), 6.75 (1H, s), 7.89 (1H, s). C NMR
1
13
C NMR (CDCl
3
, 75 MHz) d: 36.7 (C-1), 18.6 (C-2), 38.1
(
(
1
(
(
C-3), 47.7 (C-4), 44.9 (C-5), 21.9 (C-6), 29.3 (C-7), 126.8
C-8), 147.8 (C-9), 37.0 (C-10), 110.8 (C-11), 151.1 (C-12),
32.0 (C-13), 126.7 (C-14), 26.8 (C-15), 22.6 (C-16), 22.8
C-17), 179.4 (C-18), 25.1 (C-19), 16.5 (C-20), 51.9
3
(CDCl , 75 MHz) d: 37.1 (C-1), 18.3 (C-2), 37.7 (C-3), 46.8
(C-4), 44.1 (C-5), 36.5 (C-6), 197.1 (C-7), 135.6 (C-8),
155.6 (C-9), 37.8 (C-10), 104.3 (C-11), 161.8 (C-12), 124.1
(C-13), 125.8 (C-14), 26.6 (C-15), 22.4 (C-16), 22.6 (C-17),
COOCH3).
177.8 (C-18), 23.6 (C-19), 16.5 (C-20), 55.5 (OCH ), 52.2
3
1
Compound 19: H NMR (CDCl , 300 MHz) d: 1.19 (6H,
d, J = 5.1 Hz), 1.20 (3H, s), 1.26 (3H, s), 2.19 (1H, br d,
(COOCH3).
Compound 5: H NMR (CDCl
3
1
3
, 300 MHz) d: 1.31 (6H, d,
J = 9.3 Hz), 2.30 (3H, s), 2.87 (2H, m), 2.88 (1H, h,
J = 6.9 Hz), 1.59 (3H, s), 1.62 (3H, s), 2.50 (1H, br d,
1
3
J = 5.1 Hz), 3.66 (3H, s), 6.82 (1H, s), 6.93 (1H, s).
NMR (CDCl , 75 MHz) d: 36.6 (C-1), 18.5 (C-2), 37.9 (C-
), 47.6 (C-4), 44.5 (C-5), 21.6 (C-6), 29.4 (C-7), 132.9 (C-
C
J = 13.2 Hz), 3.29 (1H, h, J = 6.9 Hz), 3.96 (3H, s), 7.19
1
3
3
3
(1H, s), 7.98 (1H, s). C NMR (CDCl , 75 MHz) d: 42.7
3
8
1
(C-1), 19.6 (C-2), 36.5 (C-3), 47.8 (C-4), 146.9 (C-5), 145.7
(C-6), 173.8 (C-7), 124.9 (C-8), 152.6 (C-9), 40.1 (C-10),
108.2 (C-11), 161.9 (C-12), 137.1 (C-13), 124.7 (C-14), 27.4
(C-15), 22.7 (C-16), 22.7 (C-17), 180.8 (C-18), 21.4 (C-19),
), 146.2 (C-9), 37.0 (C-10), 117.8 (C-11), 148.1 (C-12),
37.0 (C-13), 127.0 (C-14), 27.1 (C-15), 22.9 (C-16), 23.1
(
(
C-17), 179.0 (C-18), 25.0 (C-19), 16.4 (C-20), 169.9
OCOCH ), 20.9 (OCOCH ), 51.9 (COOCH ).
3
3
3
3
24.7 (C-20), 56.3 (OCH ).