Helvetica Chimica Acta Vol. 86 (2003)
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evaporated and the residual oil purified by CC (aluminium oxide (neutral, Brockmann II), CHCl3, then CHCl3/
MeOH 97:3): 0.58 g (85%) of 1. Pale yellow oil. IR (neat): 3387, 1657, 1449, 1425, 1321, 1276, 1232, 1120, 1100,
1
1056, 1023. H-NMR: 1.82 (d, J 14.4, 2 H); 2.17 2.30 (m, 2 H); 2.27 (s, 3 H); 3.45( m, 2 H); 3.85( t, J 5.6,
1 H); 6.25( s, 2 H). 13C-NMR: 132.42, 66.02, 65.31 (CH); 41.31 (Me); 37.55 (CH2). CI-MS: 140 (45, [M 1] ),
122 (70, [M 1] À H2O] ), 113 (100, [M 1 À HCN] ).
6,7-Didehydrotropine Acetate (16). A soln. of 1 (0.12 g, 0.86 mmol) and acetyl chloride (1.10 g, 14.0 mmol)
in CHCl3 (3 ml) was refluxed for 5h. CHCl 3 and excess acetyl chloride was evaporated, and the residue was
dissolved in CHCl3 (100 ml) and washed with 10% aq. NaOH soln. (8 ml). The aq. phase was extracted with
CHCl3 (5 Â 10 ml), the combined org. phase dried (Na2SO4) and evaporated, and the residual oil purified by CC
(aluminium oxide (neutral, Brockmann II), CHCl3): 0.14 g (93%) of 16. Pale yellow oil. IR (neat): 3066, 1732,
1650, 1449, 1428, 1378, 1364, 1256, 1225, 1101, 1040, 1028. 1H-NMR: 1.69 (d, Jgem 14.6, 2 H); 1.97 (s, 3 H); 2.23
(ddd, Jgem 14.6, Jvic 6.2, 3.4, 2 H); 2.28 (s, 3 H); 3.39 (m, 2 H); 4.96 (t, Jvic 6.2, 1 H); 5.99 (s, 2 H). 13C-NMR:
170.29; 131.66; 66.89; 65.31; 41.42; 33.67; 21.43. CI-MS: 182 (55, [M 1] ), 122 (100, [M 1 À MeCOOH] ).
Acetate Scopin ( rel-(1R,2R,4S,5S)-9-Methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-ol Acetate; 6b). To a
soln. of 16 (20 mg, 0.11 mmol) in formic acid (74 ml), 90% H2O2 soln. (0.62 ml) was added at r.t. The mixture was
stirred for two days. Then more 90% H2O2 soln. (20 ml) was added, and stirring was continued at r.t. for
additional 5days. The mixture was treated with sat. aq. Na 2SO3 soln. (2 ml) and extracted with CHCl3 (20 ml).
The extract was washed with 10% aq. NaOH soln. (5ml), the aq. phase extracted with CHCl 3 (6 Â 10 ml), the
combined extract dried (Na2SO4) and evaporated, and the oily residue purified by CC (aluminium oxide
(neutral, Brockmann II), CHCl3, CHCl3/MeOH 100 :1): 6b (9 mg, 45%) and recovered 16 (10 mg, 50%). 6b:
Viscous oil. IR (neat): 1729, 1421, 1381, 1364, 1333, 1264, 1237, 1206, 1063, 1049, 1019. 1H-NMR: 1.60 (d, Jgem
15.6, 2 H); 2.02 (s, 3 H); 2.14 (ddd, Jgem 15.6, Jvic 5.5, 4.1, 2 H); 2.54 (s, 3 H); 3.19 (dd, Jvic 4.1, 1.7, 2 H); 3.63
(s, 3 H); 4.98 (t, J 5.5, 1 H). 13C-NMR: 169.98; 66.22; 58.03; 56.57; 42.37; 31.28; 21.56. CI-MS: 198 (100, [M
1] ), 138 (98, [M 1 À MeCOOH] ). Anal. calc. for C10H15NO3: C 60.91, H 7.61, N 7.10; found: C 60.69, H 7.51,
N 7.18.
6,7-Didehydrohyosciamin ((aS)-a-(Hydroxymethyl)benzeneacetic Acid (3-endo)-8-methyl-8-azabicy-
clo[3.2.1]oct-6-en-3-yl Ester; 17). To the soln. of 1 (0.11 g, 0.77 mmol) in dry Et2O (5ml), a soln. of TsOH
(0.13 g, 0.77 mmol) in dry Et2O (5ml) was added at r.t. The mixture was stirred for 40 min, and the precipitated
salt was filtered off and washed with dry Et2O (20 ml). The white crystalline TsOH salt of 1 (0.21 g, 88%) was
used in the following experiment without further purification.
Acetyltropoyl chloride ((aS)-a-(hydroxymethyl)benzeneacetyl chloride) was prepared by reaction of
acetyltropic acid (71.6 mg, 0.34 mmol) with thionyl chloride (0.19 g, 1.6 mmol) in benzene (0.1 ml) under Ar.
The mixture was heated at 608 for 2.5h. Excess thionyl chloride was evaporated, and to the oily acetyltropoyl
chloride, the TsOH salt of 1 (92.0 mg, 0.29 mmol), was added. The mixture was heated under Ar at 828 for 2.5h.
Then 6m HCl (0.33 ml) was added at r.t., the mixture stirred during 12 h and then dissolved in CHCl3/MeOH 1:1
(25ml), the soln. dried (Na 2SO4) and evaporated, and the residual oil dissolved in CHCl3/MeOH 5:1. The
precipitate was filtered off and discarded, the clear soln. evaporated, and the oily residue purified by CC (anh.
Na2SO4 2.7 g) and aluminium oxide (3.3 g; basic, Brockmann I), CHCl3/MeOH 100 :2). The obtained oil was
repurified by CC (aluminium oxide (neutral, Brockmann II), CHCl3/MeOH 100 :0.25): 19 (72 mg, 85%). Pale
yellow oil. IR (neat): 3371, 3065, 3029, 2000 1600, 1724, 1602, 1585, 1495, 1455, 1424, 1375, 1356, 1342, 1325,
1302, 1270, 1222, 1196, 1169, 1116, 1110, 1068, 1035. 1H-NMR: 1.51 (d, J 15.0, 1 H); 1.68 (d, J 15.0, 1 H); 2.13
(ddd, Jgem 15.0, Jvic 6.0, 3.6, 1 H); 2.21 (ddd, Jgem 15.0, Jvic 6.0, 3.6, 1 H); 2.20 (s, 3 H); 2.65(br. s, 1 H);
3.22 3.26 (m, 1 H); 3.32 3.36 (m, 1 H); 3.69 3.84 (m, 2 H); 4.08 4.17 (m, 1 H); 5.00 (t, J 6.0, 1 H); 5.41
(dd, J 5.5, 2.0, 1 H); 5.81 (dd, J 5.5, 1.8, 1 H); 7.21 7.38 (m, 5 H). 13C-NMR: 171.93, 135.92 (C); 131.53,
128.69, 128.27, 127.60, 67.73, 65.26, 65.18 (CH); 41.39 (Me); 33.50, 33.32 (CH2). CI-MS: 288 (100, [M 1] ), 123
(70, [M 1 À PhCH(CH2OH)COO] ). Anal. calc. for C17H21NO3: C 71.08, H 7.31; N 4.87; found: C 70.92,
H 7.24, N 4.80.
(1RS,3SR,5RS,6RS)- and (1RS,3SR,5RS,6SR)-8-(Ethoxycarbonyl)-3-hydroxy-8-azabicyclo[3.2.1]octane-
6-propanoic Acid Ethyl Ester (18). A soln. of 9 (0.15 g, 0.5 mmol), ethyl acrylate (0.50 g, 5.0 mmol), and
Bu3SnH (0.14 g, 0.5mmol) in benzene (40 ml) was irradiated with a 125-W high-pressure Hg lamp at r.t. under
Ar during 15min. Benzene was evaporated and the residue purified by CC (silica gel, petroleum ether/acetone
10 :0 ! 8 :2): 18 (46 mg, 35%), 6-endo/6-exo 55 :45 (by13C-NMR). Colorless oil. IR (neat): 3444, 1734, 1699,
1674, 1427, 1259, 1155, 1099, 1048. 1H-NMR: 1.25( t, J 7.2, 6 H); 1.40 1.90 (m, 6 H); 2.29 (t, J 7.6, 2 H);
1.90 2.70 (m, 4 H); 3.86 3.92 (br. m, 1 H); 4.12 (q, J 7.2, 2 H); 4.13 (q, J 7.2, 2 H); 4.10 4.40 (br. m, 2 H).
13C-NMR: 173.57, 154.27 (C); 64.97 (CH); 60.81, 60.31 (CH2); 57.94, 57.65, 53.15, 52.99, 41.10, 40.37 (CH); 38.38,