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Helvetica Chimica Acta Vol. 85 (2002)
with tBuOMe (4 Â 20ml), the combined org. phase washed with brine (20ml), dried (Na 2SO4), and evaporated,
20
and the residue submitted to FC (tBuOMe/pentane 1:4): 41 (3.55 g, 94%). Colorless oil. a 3.2 (c 5.48,
D
CHCl3). 1H-NMR (300 MHz, CDCl3): 0.92 (d, J 6.7, 6 H); 0.91 1.14 (m, 1 H); 1.29 1.43 (m, 1 H); 1.69
(oct., J 6.6, 1 H); 1.87 (oct., J 5.9, 1 H); 2.45 (s, 3 H); 3.05 (dd, J 12.0, 6.7, 1 H); 3.16 (dd, J 11.8, 5.4, 1 H);
3.80( dd, J 9.5, 6.1, 1 H); 3.90( dd, J 9.3, 4.1, 1 H); 6.69 (d, J 7.2, 2 H); 7.36 (d, J 8.1, 2 H). 13C-NMR
(75 MHz, CDCl3): 17.2; 18.1; 21.5; 30.3; 30.8; 37.5; 57.4; 74.5; 127.8 (2 C); 128.7; 129.8 (2 C); 144.8. Anal. calc. for
C14H21N3O3S (311.4): C 54.00, H 6.80, N 13.49; found: C 54.15, H 6.55, N 13.20.
21. (2S,4R)-5-Azido-2,4-dimethylpentyl Phenyl Sulfone (31). NaI (3.69 g, 24.6 mmol) and sodium
benzenesulfinate (7.07 g, 43.1 mmol) were added to a soln. of 41 (3.83 g, 12.3 mmol) in DMF (60ml). After
heating for 12 h to 758, H2O (60ml) was added. The aq. layer was extracted with tBuOMe (4 Â 20ml), the
combined org. phase washed with H2O (2 Â 10ml), dried (Na 2SO4), and evaporated, and the residue submitted
20
to FC (tBuOMe/pentane 1 :2): 31 (2.84 g, 82%). Colorless oil. a À1.0( c 5.12, CHCl3). 1H-NMR
D
(300 MHz, CDCl3): 0.79 (d, J 6.6, 3 H); 1.03 (d, J 6.7, 3 H); 0.97 1.10 (m, 1 H); 1.36 1.42 (m, 1 H); 1.52
1.63 (m, 1 H); 2.00 2.19 (m, 1 H); 2.83 (dd, J 14.1, 7.9, 1 H); 2.98 (dd, J 14.2, 4.2, 1 H); 3.01 (dd, J 12.0,
6.5, 1 H); 3.10( dd, J 12.1, 5.8, 1 H); 7.48 7.53 (m, 2 H); 7.57 7.62 (m, 1 H); 7.83 7.86 (m, 2 H). 13C-NMR
(75 MHz, CDCl3): 17.9; 20.7; 26.2; 30.9; 41.5; 57.3; 62.2; 127.8 (2 C); 129.3 (2 C); 133.6; 140.0. Anal. calc. for
C13H19N3O2S (281.4): C 55.49, H 6.81, N 14.93; found: C 55.45, H 6.89, N 14.75.
22. Methyl (3R,5S,6RS,7RS,8S,10R)-11-Azido-6-hydroxy-3,5,8,10-tetramethyl-7-(phenylsulfonyl)undeca-
noate. A mixture of silica gel (3 g) and pyridinium chlorochromate (1.14 g, 5.3 mmol) was added to a soln. of
ent-13 (614 mg, 3.52 mmol) in CH2Cl2 (20ml). The mixture was stirred for 2 h at r.t. and filtered. The silica gel
20
D
was washed with Et2O (20ml). The combined solns. were evaporated: ent-21 (588 mg, 97%). a 8.0( c
3.78, CHCl3). 1H-NMR (200 MHz, CDCl3): 0.99 (d, J 6.9, 3 H); 1.12 (d, J 7.0, 3 H); 1.23 1.29 (m, 1 H);
1.70 1.79 ( m, 1 H); 2.10 2.21 ( m, 2 H); 2.30 2.39 ( m, 2 H); 3.67 (s, 3 H); 9.60( d, J 2.4, 1 H). 13C-NMR
(50MHz, CDCl 3): 14.0; 20.0; 27.9; 37.5; 41.2; 44.0; 51.5; 173.1; 204.9.
A soln. of 1.47m BuLi in hexane (1.1 ml, 1.7 mmol) was added at À 788 to a soln. of 31 (512 mg, 1.82 mmol)
in THF (9 ml). After stirring for 20min, a soln. of ent-21 (156 mg, 0.91 mmol) in THF (3 ml) was added
dropwise. After stirring for 2 h at À 788, the temp. was allowed to reach À 508. Sat. aq. NH4Cl soln. (15 ml) was
added, the aq. layer extracted with tBuOMe (3 Â 10ml), the combined org. phase dried (Na 2SO4) and
evaporated, and the residue submitted to FC (tBuOMe/pentane 1:5): mixture of the hydroxysulfonyl
20
D
compounds (361 mg, 88%). Colorless oil. a À18.3 (c 12.7, CHCl3). Anal. calc. for C22H35N3O5S (453.6): C
58.25, H 7.78, N 9.26; found: C 58.54, H 7.69, N 9.32.
23. Methyl (3R,5S,6RS,7RS,8S,10R)-6-(Acetyloxy)-11-azido-3,5,8,10-tetramethyl-7-(phenylsulfonyl)unde-
canoate (43). Ac2O (2.10ml, 22.3 mmol) and DMAP (114 mg, 0.94 mmol) were added to a soln. of the
hydroxysulfonyl compounds described in Exper. 22. (1.60g, 3.6 mmol) in pyridine (20ml). The mixture was
stirred for 3 d at r.t. Sat. aq. NH4Cl soln. (30ml) was added, the aq. layer extracted with tBuOMe (5 Â 15 ml),
the combined org. phase dried (Na2SO4), and evaporated, and the residue submitted to FC (tBuOMe/pentane
1:4): diastereoisomer mixture 43 (1.50g, 87%). Colorless oil. 1H-NMR (300 MHz, CDCl3; 1:1 diastereoisomer
mixture): 0.53 (d, J 6.8, 3 H); 0.72 (d, J 6.8, 3 H); 0.87 0.93 (m, 15 H); 0.98 (d, J 6.6, 3 H); 1.10 1.32
(m, 12 H); 2.01 (s, 3 H); 2.04 (s, 3 H); 2.10 2.30 ( m, 12 H); 2.90 2.94 ( m, 1 H); 3.20 3.25 ( m, 1 H); 3.58
(s, 3 H); 3.60( s, 3 H); 4.87 4.90( m, 1 H); 5.11 (dd, J 6.4, 4.2, 1 H); 7.50 7.55 ( m, 6 H); 7.85 7.90( m, 4 H).
13C-NMR (75 MHz, CDCl3; 1:1 diastereoisomer mixture): 15.1; 15.7; 17.6; 17.7; 18.5; 18.9; 19.6; 21.1; 21.6; 21.7;
28.2; 28.5; 29.6; 31.0 (2C); 31.7; 34.4; 34.8; 39.4; 40.1; 40.3; 40.6 (2 C); 40.7; 51.8 (2 C); 57.4; 57.6; 67.5; 69.2; 72.7;
73.2; 128.2 (2 C); 128.8 (2 C); 129.1 (2 C); 129.5 (2 C); 133.8; 134.0; 140.8; 141.9; 170.2; 170.7; 173.5; 173.8.
Anal. calc. for C24H37N3O6S (459.6): C 58.16, H 7.52, N 8.48; found: C 57.98, H 7.32, N 8.47.
24. Methyl (3R,5S,6E,8S,10R)-11-(Acetylamino)-3,5,8,10-tetramethylundec-6-enoate (30). Disodium hy-
drogenphosphate (352 mg, 2.48 mmol) and 6% sodium amalgam (1.5 g) was added at À 208 to a soln. of the
isomer mixture 43 (163 mg, 0.34 mmol) in MeOH/AcOEt 2 :1 (6 ml). After stirring for 12 h at r.t., the soln. was
decanted. H2O (10ml) was added to the soln., the aq. layer extracted with tBuOMe (3 Â 10ml), the combined
org. phase dried (Na2SO4) and evaporated, and the residue submitted to FC (5% MeOH/CHCl3): 30 (62 mg,
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60%). Colorless viscous oil. a 32.7 (c 1.14, CHCl3). 1H-NMR (500 MHz, CDCl3): 0.84 (d, J 6.4, 3 H);
D
0.88 (d, J 6.6, 3 H); 0.93 (d, J 6.6, 3 H); 1.00 1.20 (m, 5 H); 1.79 1.83 (m, 2 H); 1.91 1.98 (m, 2 H); 1.98
(s, 3 H); 2.08 2.15 (m, 2 H); 2.09 (dd, J 15.4, 6.4, 1 H); 2.22 (dd, J 15.4, 4.9, 1 H); 2.98 (dd, J 13.3, 5.0,
1 H); 3.05 3.14 (m, 1 H); 3.64 (s, 3 H); 5.00 5.05 (m, 2 H); 6.41 (br. s, 1 H). 13C-NMR (125 MHz, CDCl3):
16.8; 18.6; 22.1; 22.2; 23.0; 28.0; 31.3; 34.9; 35.0; 42.0; 42.2; 44.3; 46.3; 51.4; 134.5; 135.0; 170.3; 174.2. EI-HR-
MS: 311.2457 (C18H33NO3 ; calc. 311.2460).