The Journal of Organic Chemistry
Page 6 of 15
were in good agreement with the literature.28 Rf = 0.20
1H, H-7a), 3.53-3.42 (m, 1H, H-7b), 2.96 (dd, J = 18.7, 1.3 Hz,
1
2
3
4
5
6
7
8
(hexanes/EtOAc, 1:1); IR (ATR) νmax 1766, 1181, 1066, 1026,
828 cm-1; 1H NMR (300 MHz, CDCl3) δH 5.15-5.07 (m, 1H, H-
1), 4.69 (ddd, J = 5.8, 4.5, 0.7 Hz, 1H, H-5), 4.01-3.88 (m, 2H,
H-7), 2.77 (dd, J = 18.7, 5.8 Hz, 1H, H-4a), 2.66 (dd, J = 18.7,
0.7 Hz, 1H, H-4b), 2.37-2.26 (m, 1H, H-8a), 2.27-2.07 (m, 1H,
H-8b) ppm; 13C{1H} NMR (75 MHz, CDCl3) δC 175.9, 84.4,
78.2, 67.1, 36.4, 33.2 ppm; HRMS (ESI): m/z [M+H]+ Calcd.
for:C6H9O3: 129.0552, Found: 129.0546, [M+Na]+ Calcd. for
C6H8NaO3: 151.0371, Found: 151.0366.
1H, H-4a), 2.84 (dd, J = 18.7, 6.6 Hz, 1H, H-4b), 2.45 (s, 3H,
CH3), 2.25-2.13 (m, 1H, H-8a), 1.83-1.68 (m, 1H, H-8b) ppm;
13C{1H} NMR (75 MHz, CDCl3) δC 174.9, 144.4, 134.9, 130.0,
127.3, 83.5, 60.1, 47.0, 36.8, 31.3, 21.7 ppm; HRMS (ESI): m/z
[M+H]+ Calcd. for:C13H16NO4S: 282.0800, Found: 282.0795,
[M+Na]+ Calcd. for C13H15NNaO4S: 304.0620, Found:
304.0614, [M+K]+ Calcd. for C13H15KNO4S: 320.0359, Found:
320.0353.
D-ido/D-galacto-7-methyl-8-hydroxy-2,6-
9
rac-6-(tert-Butyloxycarbonyl)-2-oxa-6-
dioxabicyclo[3.3.0]octan-3-one (22). The title compounds were
prepared according to general method 1 from mixture of
(2R,3S,4S)-hex-5-ene-2,3,4-triol and (2R,3S,4R)-hex-5-ene-
2,3,4-triol (ratio 40:60) (251 mg, 1.90 mmol). The purification
of crude product by MPLC (hexanes/EtOAc: 100/0 to 40/60
then isocratic hexanes/EtOAc: 40/60) provided desired lactones
D-ido/D-galacto (22) as inseparable mixture (183 mg, 61%,
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
azabicyclo[3.3.0]octan-3-one ((±)-10a). The title compound
was prepared according to general method 1 from amino
alcohol (±)-9a (382 mg, 1.90 mmol). The purification of crude
product by MPLC (hexanes/EtOAc: 100/0 to 60/40 then
isocratic hexanes/EtOAc: 60/40) provided desired lactone (±)-
10a (306 mg, 71%, white solid). All physical and spectral data
were in good agreement with the literature.29 Rf = 0.20
(hexanes/EtOAc, 3:2); mp 108.3-108.7, lit.29 mp 109-110 °C;
IR (ATR) νmax 1768, 1681, 1409, 1163, 770 cm-1; 1H NMR (300
MHz, CDCl3, mixture of rotamers) δH 5.05 (br s, 1H, H-1), 4.49-
4.39 (m, 1H, H-5), 3.82-3.65 (m, 1H, H-7a), 3.35 (td, J = 11.1,
6.1 Hz, 1H, H-7b), 2.90-2.67 (m, 2H, H-4), 2.29 (dd, J = 14.2,
6.1 Hz, 1H, H-8a), 2.09-1.96 (m, 1H, H-8b) 1.46 (s, 9H,
C(CH3)3) ppm; 13C{1H} NMR (75 MHz, CDCl3, mixture of
rotamers) δC 176.0, 175.6, 153.9, 153.3, 84.3, 83.3, 80.7, 58.0,
44.4, 44.1, 36.8, 36.0, 30.8, 30.3, 28.6. ppm; HRMS (ESI): m/z
[M+H]+ Calcd. for:C11H18NO4: 228.1236, Found: 228.1230,
[M+Na]+ Calcd. for C11H17NNaO4: 250.1055, Found: 250.1050,
[M+K]+ Calcd. for C11H17KNO4: 266.0795, Found: 266.0789.
rac-6-Benzyloxycarbonyl-2-oxa-6-azabicyclo[3.3.0]octan-
3-one ((±)-10b)The title compound was prepared according to
general method 1 from amino alcohol (±)-9b (446 mg, 1.90
mmol). The purification of crude product by MPLC
(hexanes/EtOAc: 100/0 to 50/50 then isocratic hexanes/EtOAc:
50/50) provided desired lactone (±)-10b (381 mg, 77%, pale
yellow solid). All physical and spectral data were in good
agreement with the literature.30 Rf = 0.20 (hexanes/EtOAc, 1:1);
mp 99.0-99.5, lit.30 mp 100-101 °C; IR (ATR) νmax 1762, 1697,
1419, 1111, 734 cm-1; 1H NMR (300 MHz, CDCl3, mixture of
rotamers) δH 7.40-7.30 (m, 5H, HAr), 5.19-5.08 (m, 3H, H-1,
PhCH2), 4.54-4.45 (m, 1H, H-5), 3.91-3.76 (m, 1H, H-7a), 3.43
(td, J = 11.1, 6.2 Hz, 1H, H-7b), 2.94-2.69 (m, 2H, H-4), 2.32
(dd, J = 14.1, 6.2 Hz, 1H, H-8a), 2.11-1.98 (m, 1H, H-8b) ppm;
13C{1H} NMR (75 MHz, CDCl3, mixture of rotamers) δC 175.6,
175.2, 154.4, 154.0, 136.3, 128.8, 128.7, 128.5, 128.3, 128.3,
128.2, 84.1, 83.1, 67.6, 67.4, 58.5, 57.9, 44.7, 44.3, 36.7, 35.8,
30.8, 30.4. ppm; HRMS (ESI): m/z [M+H]+ Calcd.
for:C14H16NO4: 262.1079, Found: 262.1074, [M+Na]+ Calcd.
for C14H15NNaO4: 284.0899, Found: 284.0893, [M+K]+ Calcd.
for C14H15KNO4: 300.0638, Found: 300.0633.
1
ratio: 60:40 from H NMR, white solid). All physical and
spectral data of D-ido 22 were in good agreement with the
literature.32 Rf = 0.20 (hexanes/EtOAc, 2:3); mp 136.8-137.3,
lit.32 mp 138-140 °C; IR (ATR) νmax 3344, 1767, 1138, 1040,
822 cm-1; D-ido (22): 1H NMR (300 MHz, CDCl3) δH 4.98 (dd,
J = 10.6, 4.9 Hz, 1H, H-1), 4.95-4.89 (m, 1H, H-5), 4.25-4.22
(m, 1H, H-8), 4.14 (qd, J = 6.3, 2.8 Hz, 1H, H-7), 2.81-2.58 (m,
2H, H-4), 2.01 (s, 1H, OH), 1.30 (t, J = 6.3 Hz, 3H, CH3) ppm;
13C{1H} NMR (75 MHz, CDCl3) δC 175.8, 88.1, 76.3, 76.0,
1
75.5, 36.0, 13.1 ppm; D-galacto (22): H NMR (300 MHz,
CDCl3) δH 4.95-4.89 (m, 1H, H-1), 4.59 (td, J = 6.1, 3.1 Hz, 1H,
H-5), 4.28-4.25 (m, 1H, H-8), 3.95 (qd, J = 6.3, 4.2 Hz, 1H, H-
7), 2.81-2.58 (m, 2H, H-4), 2.01 (s, 1H, OH), 1.30 (t, J = 6.3
Hz, 3H, CH3) ppm; 13C{1H} NMR (75 MHz, CDCl3) δC 175.4,
83.5, 79.0, 75.8, 72.1, 36.2, 14.0 ppm; HRMS (ESI): m/z
[M+H]+ Calcd. for:C7H11O4: 159.0657, Found: 159.0653,
[M+Na]+ Calcd. for C7H10NaO4: 181.0477, Found: 181.0472.
rac-(1R,5R,7S)-7-Phenyl-2,6-dioxabicyclo[3.3.0]octane-3-
one
((±)-exo-20)
and
rac-(1R,5R,7R)-7-Phenyl-2,6-
dioxabicyclo[3.3.0]octane-3-one ((±)-endo-20). The title
compounds were prepared according to general method 1 from
diol (±)-19 (338 mg, 1.90 mmol). The purification of crude
product by MPLC (hexanes/EtOAc: 100/0 to 75/25 then
isocratic hexanes/EtOAc: 75/25) provided desired lactones (±)-
exo-20 (178 mg, 46%, orange oil) and (±)-endo-20 (58 mg,
15%, orange oil). All physical and spectral data of (±)-exo-20
were in good agreement with the literature.33 (±)-exo-20: Rf =
0.20 (hexanes/EtOAc, 7:3); IR (ATR) νmax 1774, 1171, 1059,
1
944, 754 cm-1; H NMR (300 MHz, CDCl3) δH 7.41-7.27 (m,
5H, HAr), 5.24 (t, J = 4.8 Hz, 1H, H-1), 5.13 (dd, J = 10.6, 4.8
Hz, 1H, H-7), 5.05 (ddd, J = 5.8, 4.8, 1.6 Hz, 1H, H-5), 2.91-
2.79 (m, 2H, H-4), 2.71 (dd, J = 14.2. 4.8 Hz, 1H, H-8a), 2.10-
1.98 (m, 1H, H-8b) ppm; 13C{1H} NMR (75 MHz, CDCl3) δC
176.0, 140.0, 128.8, 128.2, 125.9, 85.0, 79.8, 78.4, 41.7, 36.8
ppm; HRMS (ESI): m/z [M+H]+ Calcd. for:C12H13O3: 205.0865,
Found: 205.0858, [M+Na]+ Calcd. for C12H12NaO3: 227.0684,
Found: 227.0678, [M+K]+ Calcd. for C12H12KO3: 243.0424,
Found: 243.0417; (±)-endo-20: Rf = 0.20 (hexanes/EtOAc, 7:3);
IR (ATR) νmax 1775, 1194, 1029, 754, 581 cm-1; 1H NMR (300
MHz, CDCl3) δH 7.41-7.27 (m, 5H, HAr), 5.14 (ddd, J = 7.0, 4.6,
2.4 Hz, 1H, H-1), 4.97 (dd, J = 8.3, 7.6 Hz, 1H, H-7), 4.69 (td,
J = 4.6, 1.6 Hz, 1H, H-5), 2.93-2.82 (m, 2H, H-4), 2.82-2.74 (m,
1H, H-8a), 2.26 (ddd, J = 14.5, 8.3, 2.4 Hz, 1H, H-8b) ppm;
13C{1H} NMR (75 MHz, CDCl3) δC 175.4, 140.1, 128.8, 128.3,
126.2, 84.7, 81.8, 79.0, 41.1, 36.3 ppm; HRMS (ESI): m/z
[M+H]+ Calcd. for:C12H13O3: 205.0865, Found: 205.0859,
rac-6-Tosyl-2-oxa-6-azabicyclo[3.3.0]octan-3-one
((±)-
10c). The title compound was prepared according to general
method 1 from amino alcohol (±)-9c (485 mg, 1.90 mmol). The
purification of crude product by MPLC (hexanes/EtOAc: 100/0
to 50/50 then isocratic hexanes/EtOAc: 50/50) provided desired
lactone (±)-10c (433 mg, 81%, white solid). All physical and
spectral data were in good agreement with the literature.31 Rf =
0.20 (hexanes/EtOAc, 1:1); mp 131.9-132.5, lit.31 mp 133-134
1
°C; IR (ATR) νmax 1773, 1335, 1156, 973, 573 cm-1; H NMR
(300 MHz, CDCl3) δH 7.75-7.68 (m, 2H, HAr), 7.35 (dd, J = 8.6,
0.7 Hz, 2H, HAr), 4.96 (td, J = 5.4, 1.4 Hz, 1H, H-1), 4.37 (ddd,
J = 6.6, 5.4, 1.3 Hz, 1H, H-5), 3.58 (ddd, J = 11.3, 8.6, 2.7 Hz,
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