5990
M. K. Singh et al. / Tetrahedron Letters 48 (2007) 5987–5990
3
-Formyl-2(1H)-quinolone 2a: Yield: 93%; solid; mp 303–
(0.82 mmol) at room temperature and the reaction was
stirred for 45 min. The reaction mixture was extracted
with EtOAc and the combined organics washed with
À1
1
304 ꢁC. IR (KBr): 1620, 1684, 3323 cm
.
H NMR
(
300 MHz; DMSO-d ): d = 7.25 (t, 1H, J = 7.2 Hz, H-7),
6
7
6
.35 (d, 1H, J = 6.0 Hz, H-8), 7.66 (t, 1H, J = 6.6 Hz, H-
), 7.92 (d, 1H, J = 6.0 Hz, H-5), 8.51 (s, 1H, H-4), 10.24
2 4
water, brine and dried over Na SO . Evaporation of
the solvent under vacuum and purification of the
products using silica gel column chromatography employ-
ing hexane–EtOAc (75:25, v/v) as eluent gave pure 5a and
6a.
(
s, 1H, CHO), 12.24 (s, 1H, NH, D
2
O exchangeable).
Anal. Calcd for C H NO : C, 69.36; H, 4.07; N, 8.09.
1
0
7
2
Found: C, 69.14; H, 3.92; N, 7.93.
3. To a suspension of formyl quinolone 2 (1 mmol) in DMF–
1
trans-2-Iodomethyl-4-hydroxy-4H-2,3-dihydropyrano[2,3-b]-
quinoline 5a: White solid; Yield: 30%; mp 138–139 ꢁC. IR
water (8–10 ml) was added indium powder (2 mmol) and
allyl bromide (3 mmol), and the mixture stirred at room
temperature for a time ranging between 4 and 12 h. After
completion (checked by TLC), the reaction was quenched
with a few drops of 2 N HCl, diluted with water and
extracted with EtOAc. The organic layer was dried over
À1
1
(KBr): 1626, 1235, 1161 cm
CDCl
11.5, 14.2 Hz, CH
14.2 Hz, CH equatorial), 3.60 (m, 2H, CH I), 4.61 (m,
.
H NMR (300 MHz;
3
): d = 2.05 (br s, 1H, OH), 2.08 (ddd, 1H, J = 3.0,
axial), 2.40 (ddd, 1H, J = 3.0, 3.0,
2
2
2
2
1H, CHCH I), 5.10 (dd, 1H, J = 3.0, 6.3 Hz, CHOH),
MgSO
was characterized and used without further purification.
-(1-Hydroxy-but-3-en-1-yl)-2-quinolone 3a: White solid;
4
and concentrated in vacuum. The crude product
7.41 (t, 1H, J = 7.4 Hz, 6-H), 7.66 (t, 1H, J = 7.6 Hz, 7-
H), 7.74 (d, 1H, J = 7.8 Hz, 5-H), 7.90 (d, 1H, J = 7.8 Hz,
8-H), 8.12 (s, 1H, 5-H). C NMR (75 MHz; CDCl3):
d = 8.0, 35.8, 63.5, 71.4, 119.7, 124.6, 125.2, 127.2, 127.4,
2
130.5, 139.7, 147.0, 158.8. Anal. Calcd for C13H12NO I: C,
1
3
3
À1
1
Yield: 90%; mp 188 ꢁC. IR (KBr): 1664 cm . H NMR
(
300 MHz; DMSO-d
6
): d = 2.23–2.33 (m, 2H, CH
2
), 4.80
(
br s, 1H, @CH ), 4.96 (s, 1H, @CH ), 5.05 (d, 1H,
45.77; H, 3.55; N, 4.11. Found: C, 45.65; H, 3.20; N,
4.33.
10-Aza-12,15-dioxa-tetracyclo(11,2,1,0 ,0 )hexdeca-2,
2
2
J = 7.5 Hz, CHOH), 5.25 (d, 1H, J = 4.5, 7.5 Hz, OH,
O exchangeable), 5.85 (m, 1H, CH@CH ), 7.20 (t, 1H,
J = 7.5 Hz, 6-H), 7.35 (d, 1H, J = 8.1 Hz, 5-H), 7.50 (t,
H, J = 7.5 Hz, 7-H), 7.70 (d, 1H, J = 7.8 Hz, 8-H), 7.80
2
,11 4,9
D
2
2
4,6,8,10-pentene 6a: White solid; Yield: 63%; mp 96 ꢁC. IR
À1
1
1
(KBr): 1626, 1416, 1200 cm
.
H NMR (300 MHz;
1
3
(
s, 1H, 4-H), 11.75 (s, 1H, NH, D
2
O exchangeable).
C
CDCl
CH axial), 2.43 (d, 1H, J = 12.3 Hz, 16-CH
1H, J = 3.6, 10.5 Hz, 14-CH ), 4.33 (d, 1H, J = 10.5 Hz,
3
): d = 2.27 (ddd, 1H, J = 3.0, 4.8, 12.3 Hz, 16-
NMR (75 MHz; DMSO-d
1
6
): d = 40.8, 67.2, 115.3, 117.6,
2
2
eq), 4.12 (dd,
19.7, 122.8, 128.3, 130.4, 135.2, 135.7, 136.6, 137.8, 161.7.
2
Anal. Calcd for C H NO : C, 72.54; H, 6.09; N, 6.51.
14-CH ), 5.16 (d, 1H, J = 4.8 Hz, 1-CH), 5.22 (br s, 1H,
1
3
13
2
2
Found: C, 72.23; H, 5.91; N, 6.43.
13-CH), 7.38 (t, 1H, J = 7.5 Hz, 6-H), 7.63 (t, 1H,
J = 7.5 Hz, 7-H), 7.70 (d, 1H, J = 7.8 Hz, 5-H), 7.82 (s,
1
4. To a stirred solution of 3 (0.44 mmol) in THF (15 ml) were
added I (0.93 mmol) and NaHCO (1.014 mmol) under a
1
3
2H, 3-H, 8-H). C NMR (75 MHz; CDCl ): d = 32.8,
2
3
3
nitrogen atmosphere at room temperature and the reac-
tion stirred for 4 h. After the reaction had finished
74.3, 75.1, 77.5, 122.4, 124.5, 124.8, 127.2, 127.4, 129.9,
135.1, 147.2, 158.9. MS: m/z = 214 (M+1). Anal. Calcd
(
(
(
monitored by TLC), a saturated aq solution of Na
10 ml) was added. The solution was diluted with water
15 ml), and extracted with EtOAc (3 · 20 ml). The
2
SO
3
2
for C13H11NO : C, 73.23; H, 5.20; N, 6.57. Found: C,
72.89; H, 5.09; N, 6.45. See also Yadav, J. S.; Reddy, B. V.
S.; Meraj, S.; Vishnumurthy, P.; Narsimulu, K.; Kunwar,
A. C. Synthesis 2006, 2923–2926.
organic layers were pooled and washed with brine
(
15 ml) and dried over anhydrous MgSO
4
and evaporated
16. A mixture of 4a/5a (0.44 mmol) and DBU (0.88 mmol) in
20 ml of benzene was stirred for 12 h. After completion of
reaction (monitored by TLC), the reaction mixture was
filtered and the filtrate was washed with dil HCl, brine and
to yield a residue, which was purified via silica gel
chromatography employing hexane–EtOAc (70:30, v/v)
as eluent to afford inseparable products 4/5 as a solid.
cis-2-Iodomethyl-4-hydroxy-4H-2,3-dihydropyrano[2,3-b]-
quinoline 4a: White solid; Yield: 88%; mp 133–134 ꢁC. IR
2 4
dried over anhydrous Na SO . Evaporation of the solvent
under vacuum and purification of the products using silica
gel column chromatography employing hexane–EtOAc
(60:40, v/v) as eluent gave pure 6a and 7a.
À1
1
(
KBr): 1626, 1259, 1192 cm
.
H NMR (300 MHz;
CDCl
3
): d = 1.90 (q, 1H, J = 12.0 Hz, CH axial), 2.20
2
(
d, 1H, J = 7.5 Hz, OH), 2.70 (ddd, 1H, J = 1.8, 5.4,
2-Methylene-3,4-dihydro-2H-1-oxa-9-aza-anthracen-4-ol 7a:
1
CH
2.0 Hz, CH2 equatorial), 3.51 (dd, 1H, J = 6.9, 10.5,
I), 3.60 (dd, 1H, J = 4.2, 10.5, CH I), 4.40 (m, 1H,
CHCH ), 5.20 (m, 1H, CHOH), 7.40 (t, 1H, J = 7.2 Hz,
-H), 7.70 (t, 1H, J = 7.2 Hz, 7-H), 7.75 (d, 1H,
J = 6.6 Hz, 5-H), 7.87 (d, 1H, J = 8.4 Hz, 8-H), 8.32 (s,
White solid; Yield: 38%; mp 98 ꢁC. IR (KBr): 3201, 1424,
À1
1
2
2
1253 cm . H NMR (300 MHz; CDCl
3
): d = 2.08 (d, 1H,
),
2.91 (dd, 1H, J = 3.9, 13.8 Hz, CH ), 4.50 (s, 1H, @CH ),
2
J = 6.9 Hz, OH), 2.78 (dd, 1H, J = 7.2, 13.8 Hz, CH
2
6
2
2
2
4.98 (s, 1H, @CH ), 5.04 (d, 1H, J = 5.1 Hz, CHOH), 7.44
13
1
7
1
C
4
H, 5-H). C NMR (75 MHz; CDCl
3
): d = 7.1, 37.4, 65.2,
(t, 1H, J = 7.5 Hz, 6-H), 7.68 (t, 1H, J = 6.9 Hz, 7-H),
7.78 (d, 1H, J = 8.1 Hz, 5-H), 7.91 (d, 1H, J = 8.4 Hz, 8-
4.3, 122.2, 124.7, 125.5, 127.3, 127.4, 130.2, 136.6, 146.6,
58.5. MS: m/z = 342 (M+1). Anal. Calcd for
1
3
H), 8.21 (s, 1H, 10-H). C NMR (75 MHz; CDCl3):
d = 35.6, 64.5, 95.7, 121.3, 125.1, 125.6, 127.5, 130.4,
137.3, 146.8, 148.8, 151.3, 156.9. Anal. Calcd for
C H NO : C, 73.23; H, 5.20; N, 6.57. Found: C, 72.93;
13
H12NO
2
I: C, 45.77; H, 3.55; N, 4.11. Found: C,
5.81; H, 3.23; N, 3.98.
1
5. To a stirred solution of 4a/5a (0.42 mmol) in CH CN–
3
13 11
2
H O (9:1 ml) was added a 1 M solution of aq NaOH
2
H, 5.05; N, 6.49.