3
1
3
.48 (m, 1 H), 3.68 (m, 1 H), 3.73 (s, 3 H), 4.09 (m, 3 H), 4.23 (d, 1 H, J = 14.8 Hz), 4.68 (d, 1 H, J =
1
3
4.8 Hz), 6.78 (d, 2 H, J = 8.1 Hz), 7.13 (d, 2 H, J = 8.1 Hz); C NMR (CDCl3, 50 MHz) δ 23.9, 25.8,
+
6.9, 43.7, 44.6, 54.5, 54.9, 62.1, 69.7, 113.9, 128.6, 129.0, 158.9, 174.6; MS: m/z 457 (M ). Anal. Calcd
for C21
H
35NO SSi: C, 55.14; H, 7.65; S, 7.0. Found: C, 54.80; H, 7.58; S, 6.92.
6
Further elution gave 9 (4.5 g, 50 %) which was mesylated with mesyl chloride (1.5 mL, 19.6 mmol) and
1
Et
3
N (5 mL) as described above, to give 11 (3.2 g, 83 %) as an oil: H NMR (CDCl
3
, 200 MHz) δ 0.03
(
s, 6 H), 0.84 (s, 9 H), 1.93 (m, 1 H), 2.24 (m, 1 H), 2.67 (m, 1 H), 2.89 (s, 3 H), 3.65-3.74 (m, 3 H), 3.74
(
s, 3 H), 3.93 (m, 2 H), 4.08 (d, 1 H, J = 14.5 Hz), 4.92 (d,1 H, J = 14.5 Hz), 6.80 (d, 2 H, J = 8.6 Hz),
1
3
7
6
7
.14 (d, 2 H, J = 8.6 Hz); C NMR (CDCl3, 50 MHz) δ 24.7, 25.7, 37.5, 42.6, 44.3, 54.5, 55.2, 62.4,
+
8.2,114.3, 127.9, 129.2, 154.3, 176.2. MS: m/z 457 (M ). Anal. Calcd for C21
.65; S, 7.0. Found: C, 54.60; H, 7.53; S, 6.92.
H
35NO SSi: C, 55.14; H,
6
(
5S*)-N-(4-Methoxybenzyl)-3-methylene-5-hydroxymethylpyrolidin-2-one (8):
To a solution of 11 (2.0 g, 4.4 mmol) in THF (20 mL) was added 1 M solution of Bu
.6 mmol). The mixture was stirred at rt for 2 h. After addition of saturated NH Cl, the organic layer was
4
NF in THF (6.6 mL,
6
4
separated, concentrated and chromatographed on silica gel eluting with EtOAc-hexane (3:2) to give 8
1
(
0.97 g, 90 %). H NMR (CDCl
3
, 200 MHz) δ 2.72 (m, 2 H), 3.52 (m, 2 H), 3.77 (s, 3 H), 3.82 (m, 2 H),
4
6
6
6
.12 (d,1 H, J = 14.9 Hz ), 4.93 (d, 1 H, J = 14.7 Hz), 5.33 (t, 1 H, J = 2.1 Hz), 5.98 (t, 1 H, J = 2.7 Hz),
13
.81 (d, 2 H, J = 8.8 Hz), 7.16 (d, 2 H, J = 8.8 Hz); C NMR (CDCl3, 50 MHz) δ 26.7, 43.5, 54.3, 54.6,
+
1.1, 113.2, 114.6, 127.6, 128.6, 138.8, 158.2, 167.9; MS: m/z 247 (M ). Anal. Calcd for C14
H
17NO : C,
3
8.01; H, 6.88; N, 5.66. Found: C, 67.68; H, 6.88; N, 5.49.
Compound (8) (96%) was also obtained from 5 by refluxing with 2 N NaOH in MeCN for 2 h.
(
3S*, 6R*)-1-(4-Methoxybenzyl)-5-oxa-1-azabicyclo[3.2.1]octan-2-one (13):
Compound (12) (2.1 g, 4.6 mmol) and 1 M solution of Bu NF in THF (6.8 mL, 6.8 mmol) was stirred at
4
rt for 2 h and concentrated. The residue was partitioned between extracted with ethylacetate and water,
dried (Na
2
SO
4
) and concentrated. The residue was chromatographed on silica gel eluting with EtOAc-
1
hexane (3:2) to give 13 (0.97 g, 85 %) as a syrup: H NMR (CDCl
3
, 200 MHz) δ 1.83 (d, 1 H, J = 10.7
Hz), 2.29 (m, 2 H), 2.47 (br s, 1 H), 2.70 (m,1 H), 3.45 (d,1 H, J = 11.4 Hz), 3.58 (d, 1 H, J = 11.4 Hz),
.79 (s, 3 H), 3.98 (m, 1 H), 4.04 (d, 1 H, J = 14.9 Hz), 4.82 (d, 1 H, J = 14.9 Hz), 6.84 (d, 2 H, J = 9.3
3
1
3
Hz), 7.19 (d, 2 H, J = 9.3 Hz); C NMR (CDCl3 , 50 MHz) δ 34.2, 40.9, 42.8, 53.6, 53.8, 62.9, 65.8,
+
1
5
12.8, 127.54 ,127.9, 157.9, 173.9; MS: m/z 247 (M ). Anal. Calcd for C14
.66. Found: C, 67.91; H, 6.65; N, 5.41.
H
17NO : C, 68.01; H, 6.88; N,
3