6086
N. Watanabe et al. / Tetrahedron 68 (2012) 6079e6087
(d, J¼2.3 Hz, 2H), 6.72e6.73 (m, 1H), 6.75 (dd, J¼7.8 and 1.8 Hz, 2H),
7.11e7.16 (m, 2H), 7.85 (dd, J¼8.2 and 1.8 Hz, 1H), 8.31 (d, J¼1.4 Hz,
1H) ppm; 13C NMR (125 MHz, CD3OD): dC 24.0, 28.0 (ꢁ2), 28.2 (ꢁ2),
30.5, 38.0, 38.3, 48.3, 50.1, 71.8, 80.9, 84.2, 103.8 (ꢁ2), 111.8 (ꢁ2),
114.0 (ꢁ2), 116.4 (ꢁ2), 118.3, 122.7, 123.9, 126.0, 128.3, 129.3, 130.1,
130.5 (ꢁ2), 138.5, 142.0, 148.9 (br), 152.7, 154.4 (ꢁ2), 158.1, 161.7
~
1313, 1179, 1115 cmꢂ1; HRMS (ESI): 692.2869, calcd for C41H42NO9
[MþH]þ 692.2860, 714.2687, calcd for C41H41NO9Na [MþNa]þ
714.2679.
4.2.18. 5-[7-(Fluorescein-5-yl)carbamoyl-1,1-dimethyl-3-oxaheptyl]-
1-(3-hydroxyphenyl)-4,4-dimethyl-2,6,7-trioxabicyclo[3.2.0]heptane
(3). Dihydrofuran 21 (100 mg, 0.145 mmol) was irradiated in the
presence of TPP (1.0 mg) externally with a 940 W Na-lamp in
CH2Cl2 (10 ml) and CH3OH (10 drops) under an O2 atmosphere at
0 ꢀC for 1 h. The photolysate was concentrated in vacuo. The residue
was chromatographed on SiO2 and eluted with CH2Cl2/ether to give
dioxetane 3 in 84.6% yield (88.8 mg). Amorphous orange solid; 1H
NMR (500 MHz, CD3OD): dH 0.87 (s, 3H),1.13 (s, 3H),1.17 (s, 3H),1.39
(s, 3H), 1.56e1.66 (m, 2H), 1.72e1.84 (m, 2H), 2.45 (t, J¼7.3 Hz, 2H),
3.25 (d, J¼9.2 Hz, 1H), 3.33e3.40 (m, 3H), 3.38 (d, J¼9.2 Hz, 1H),
3.79 (d, J¼8.0 Hz, 1H), 4.47 (d, J¼8.0 Hz, 1H), 6.53 (dd, J¼8.7 and
2.3 Hz, 2H), 6.63 (d, J¼8.7 Hz, 2H), 6.60 (d, J¼2.3 Hz, 2H), 6.80e6.85
(m, 1H), 7.05 (s, 1H), 7.06 (d, J¼7.9 Hz, 1H), 7.14 (d, J¼8.2 Hz, 1H),
7.22 (dd, J¼8.2 and 7.9 Hz, 1H), 7.86 (dd, J¼8.2 and 1.8 Hz, 1H), 8.31
(d, J¼1.8 Hz, 1H) ppm; 13C NMR (125 MHz, CD3OD): dC 18.5, 21.6,
23.3, 24.0 (ꢁ2), 25.3, 30.3, 38.0, 42.5, 46.9, 72.1, 77.7, 81.4, 103.8
(ꢁ2), 106.6, 111.8 (ꢁ2), 114.0 (br, ꢁ2), 116.4 (br), 116.8, 117.8, 118.5,
121.0, 126.0, 128.4, 129.4, 130.3, 130.5 (ꢁ2), 138.9, 142.1, 149.0 (br),
~
(ꢁ2), 171.6, 175.2 ppm; IR (KBr):
n
3393, 2957, 2869, 1735, 1607,
4.2.16. 4-{7-[N-(4-Benzothiazol-2-yl)-3-hydroxyphenyl]methyl-
carbamoyl]-1,1-dimethyl-3-oxahept-1-yl}-5-(3-tert-butyldimethylsi-
lyloxyphenyl)-3,3-dimethyl-2,3-dihydrofuran (23). 2-(4-Aminomethyl-
2-methoxyphenyl)benzothiazole (320 mg, 1.18 mmol) and Et3N
(0.20 mL, 1.43 mmol) were added to a solution of N-hydrox-
ysuccinimide ester 6 (602 mg, 1.05 mmol) in CH3CN (6 mL) under
a nitrogen atmosphere at room temperature and stirred for 5 h. The
reaction mixture was concentrated in vacuo. The residue was
chromatographed on silica gel and eluted with AcOEt/hexane (1:2)
to give amide 23 as a colorless oil in 86.3% yield (661 mg); 1H NMR
(400 MHz, CDCl3): dH 0.17 (s, 6H), 0.97 (s, 9H), 1.03 (s, 6H), 1.29 (s,
6H),1.55e1.64 (m, 2H),1.71e1.80 (m, 2H), 2.30 (t, J¼7.4 Hz, 2H), 3.10
(s, 2H), 3.27 (t, J¼6.1 Hz, 2H), 3.84 (s, 2H), 4.02 (s, 3H), 4.49 (d,
J¼5.9 Hz, 2H), 5.95 (br s, 1H), 6.74e6.79 (m, 1H), 6.77 (s, 1H), 6.89 (d
with fine coupling, J¼7.7 Hz, 1H), 6.98 (s, 1H), 7.00 (d, J¼7.9 Hz, 1H),
7.15 (t, J¼7.7 Hz, 1H), 7.37 (dd with fine coupling, J¼8.2 and 7.2 Hz,
1H), 7.49 (dd with fine coupling, J¼8.2 and 7.2 Hz, 1H), 7.92 (d with
fine coupling, J¼7.9 Hz, 1H), 8.07 (d with fine coupling, J¼8.2 Hz,
1H), 8.47 (d with fine coupling, J¼7.9 Hz, 1H) ppm; 13C NMR
(125 MHz, CDCl3): dC ꢂ4.4 (ꢁ2), 18.1, 22.9, 25.6 (ꢁ3), 27.2 (ꢁ2), 27.4
(ꢁ2), 29.0, 36.4, 37.0, 43.3, 47.0, 55.7, 70.7, 79.7, 83.0, 111.0, 119.8,
120.2, 121.2, 121.4, 121.7, 122.3, 122.7, 123.0, 124.6, 125.9, 128.7,
129.7, 136.0, 137.1, 142.8, 151.0, 152.1, 155.0, 157.3, 162.8, 172.9 ppm;
~
154.5 (ꢁ2), 158.5, 161.7 (brꢁ2), 171.6, 175.1 ppm; IR (KBr):
n
3353,
2925, 2871, 1735, 1671, 1606, 1312, 1114 cmꢂ1
; HRMS (ESI):
746.2553, calcd for C41H41NO11Na [MþNa]þ 746.2577.
4.2.19. 5-{7-[N-(4-Benzothiazol-2-yl)-3-hydroxyphenyl]methyl-
carbamoyl]-1,1-dimethyl-3-oxahept-1-yl}-1-(3-hydroxyphenyl)-4,4-
dimethyl-2,6,7-trioxabicyclo[3.2.0]heptane (4). A solution of dihy-
drofuran 24 (150 mg, 0.250 mmol) and TPP (3 mg) in CH2Cl2 (10 ml)
was irradiated externally with 940 W Na-lamp under an oxygen
atmosphere at 0 ꢀC for 1 h. The photolysate was concentrated in
vacuo. The residue was chromatographed on silica gel and eluted
with CH2Cl2 and ether/CH2Cl2 (1:1) to give dioxetane 4 in quanti-
tative yield. Compound 4: Colorless amorphous solid; 1H NMR
(400 MHz, CDCl3): dH 0.87 (s, 3H), 1.04 (s, 3H), 1.12 (s, 3H), 1.35 (s,
3H), 1.50e1.82 (m, 4H), 2.27e2.43 (m, 2H), 3.23 (d, J¼9.3 Hz, 1H),
3.29e3.42 (m, 2H), 3.57 (d, J¼9.3 Hz, 1H), 3.80 (d, J¼8.0 Hz, 1H),
4.45e4.55 (m, 2H), 4.54 (d, J¼8.0 Hz, 1H), 6.35 (t, J¼5.6 Hz,1H), 6.89
(d with fine coupling, J¼8.1 Hz, 1H), 6.96 (d with fine coupling,
J¼8.1 Hz, 1H), 7.06e7.10 (m, 2H), 7.22e7.28 (m, 2H), 7.41(dd with
fine coupling, J¼7.9 and 7.3 Hz, 1H), 7.51 (dd with fine coupling,
J¼8.1 and 7.3 Hz, 1H), 7.67 (d, J¼8.1 Hz, 1H), 7.90 (d with fine cou-
pling, J¼7.9 Hz, 1H), 7.99 (d with fine coupling, J¼8.1 Hz, 1H), 12.72
(br s, 1H) ppm; 13C NMR (125 MHz, CDCl3): dC 18.0, 20.9, 22.4, 23.5,
24.6, 28.2, 36.0, 40.8, 43.2, 45.5, 71.5, 76.9, 80.0, 105.6, 115.7, 115.8,
116.6,116.8,116.9,119.2,119.9, 121.4, 122.0, 125.5, 126.6, 128.7, 129.2,
~
IR (liquid film):
n
3299, 2955, 2930, 2859, 1649, 1577, 1463, 1419,
1264, 1125, 940 cmꢂ1; Mass (m/z, %): 728 (Mþ, 1), 346 (31), 345
(100), 254 (10), 235 (13); HRMS (ESI): 729.3747, calcd for
C42H57N2O5SSi [MþNa]þ 729.3757.
4.2.17. 4-{7-[N-(4-Benzothiazol-2-yl)-3-hydroxyphenyl]methyl-
carbamoyl]-1,1-dimethyl-3-oxahept-1-yl}-5-(3-hydroxyphenyl)-3,3-
dimethyl-2,3-dihydrofuran (24). CH3SNa (95%, 211 mg, 2.86 mmol)
was added to a solution of amide 23 (493 mg, 0.676 mmol) in dry
DMF (5 mL) under a nitrogen atmosphere at room temperature and
stirred at 140 ꢀC for 1 h. The reaction mixture was poured into satd
aq NH4Cl and extracted with AcOEt. The organic layer was washed
three times with satd aq NaCl, dried over anhydrous MgSO4, and
concentrated in vacuo. The residue was chromatographed on silica
gel and eluted with AcOEt/hexane (2:1) to give amide 24 in 94.8%
yield (385 mg). Colorless granules mp 132.5e133.0 ꢀC (from AcOEt/
hexane); 1H NMR (500 MHz, CDCl3): dH 1.01 (s, 6H), 1.29 (s, 6H),
1.57e1.64 (m, 2H), 1.77e1.90 (m, 2H), 2.35 (t, J¼7.2 Hz, 2H), 3.10 (s,
2H), 3.29 (t, J¼5.7 Hz, 2H), 3.85 (s, 2H), 4.50 (d, J¼5.8 Hz, 2H), 5.91
(br s, 1H), 6.77e6.83 (m, 1H), 6.83 (d with fine coupling, J¼8.2 Hz,
1H), 6.90 (dd, J¼7.9 and 1.5 Hz, 1H), 7.00 (s with fine coupling, 1H),
7.03 (s with fine coupling,1H), 7.16 (t, J¼7.9 Hz, 1H), 7.42 (t with fine
coupling, J¼7.9 Hz, 1H), 7.51 (t with fine coupling, J¼7.9 Hz, 1H),
7.66 (d, J¼8.2 Hz, 1H), 7.91 (d, J¼7.9 Hz, 1H), 7.99 (d, J¼7.9 Hz, 1H),
8.32 (s, 1H), 12.60 (br s, 1H) ppm; 13C NMR (125 MHz, CDCl3): dC
22.9, 27.2 (ꢁ2), 27.7 (ꢁ2), 29.2, 36.1, 37.1, 43.3, 46.9, 70.3, 79.3, 82.9,
115.4, 115.8, 116.4, 117.3, 118.9, 121.1, 121.4, 121.4, 122.0, 125.5, 126.6,
128.7, 128.8, 132.5, 136.9, 143.2, 151.2, 151.6, 156.3, 157.9, 168.9,
~
132.5, 136.9, 143.8, 151.6, 156.4, 157.7, 169.0, 174.1 ppm. IR (KBr):
n
3342, 2948, 2872, 1632, 1583, 1481, 1316, 1216, 759 cmꢂ1; Mass (m/
z, %): 632 (Mþ, 89), 482 (12), 356 (22), 355 (10), 340 (12), 339 (58),
326 (11), 278 (35). 257 (17), 256 (30), 255 (100), 241 (12), 240 (14),
228 (11), 227 (18), 221 (26), 121 (26), 100 (45), 94 (55), 83 (24), 71
(10), 56 (11); HRMS (ESI): 655.2434, calcd for C35H40N2O7SNa
[MþNa]þ 655.2454.
4.3. Measurement of chemiluminescence and time-course of
the base-induced decomposition of dioxetanes: general
procedure
Chemiluminescence was measured using a JASCO FP-750 and/or
FP-6500 spectrometer, and a Hamamatsu Photonics PMA-11 multi-
channel detector.
4.3.1. TBAF/acetonitrile system. A freshly prepared solution
(2.00 mL) of TBAF (1.0ꢁ10ꢂ2 mol/L) in acetonitrile was transferred
to a quartz cell (10ꢁ10ꢁ50 mm), which was placed in a spectrom-
eter that was thermostated with stirring at 25 ꢀC. After 3e5 min,
a solution of dioxetane 3 or 4 in acetonitrile (1.0ꢁ10ꢂ4 mol/L,
1.00 mL) was added by means of a syringe, and measurement was
173.9 ppm. IR (KBr): 3316, 2955, 2929, 2865, 1634, 1578, 1481,
n
1440, 1215, 759 cmꢂ1; Mass (m/z, %): 600 (Mþ, 1), 255 (13), 244 (15),
232 (17), 231 (100); HRMS (ESI): 623.2517, calcd for C35H40N2O5SNa
[MþNa]þ 623.2556.