LETTER
Modified Julia–Kocienski Reaction
829
(neat): 837, 1101, 1157, 1352, 1539, 2929 cm–1; 1H NMR
(500 MHz, CDCl3): d = 0.28 (s, 6 H), 1.01 (s, 9 H), 3.27 (t,
J = 8.2 Hz, 2 H), 4.07 (t, J = 8.2 Hz, 2 H), 6.83 (d, J = 8.0
Hz, 1 H), 6.91 (t, J = 8.0 Hz, 1 H), 7.18 (t, J = 8.0 Hz, 1 H),
7.20 (d, J = 8.0 Hz, 1 H), 7.84 (t, J = 8.5 Hz, 1 H), 8,09 (dt,
J = 8.5, 1.0 Hz, 1 H), 8.51 (dt, J = 8.5, 1.0 Hz, 1 H), 8.61 (t,
J = 1.0 Hz, 1 H); 13C NMR (125 MHz, CDCl3): d = –4.0,
18.3, 24.4, 25.9, 55.7, 118.7, 120.8, 121.5, 126.2, 126.4,
128.9, 130.8, 130.9, 131.0, 133.9, 148.7, 153.7, 154.0; FAB-
MS: m/z = 490 [M + H]+; HRMS: m/z [M + H]+ calcd for
C21H28O5N5SSi: 490.1580; found: 490.1595.
N
N
N N
O
O
N
N
O
O
S
S
N
N
base
MeO
MeO
NO2
NO2
20
MeO
N
N
O
O
O
N
O
S
N
N
S
N
N
HN
(12) Synthesis of 16: To a stirred solution of sulfone 14 (11 mg,
22 mmol), aldehyde 15 (13 mg, 26 mmol) and LiCl (4.0 mg,
78 mmol) in MeCN (1.0 mL) at 0 °C, DBU (12 mL, 78 mmol)
was added dropwise. After stirring for 20 min, the reaction
mixture was quenched with sat. aq NH4Cl and extracted with
CH2Cl2. The organic layer was washed with sat. aq NH4Cl
and brine, dried over MgSO4, and concentrated in vacuo.
The residue was purified by preparative TLC to yield 16
(11 mg, 18 mmol, 81%). Spectral data for 16: IR (neat): 839,
1116, 1573, 1693, 2927 cm–1; 1H NMR (500 MHz, CDCl3):
d = 0.25 (s, 6 H), 1.02 (s, 9 H), 3.50 (d, J = 7.3 Hz, 2 H), 5,04
(s, 2 H), 5.08 (s, 4 H), 6.25–6.27 (m, 2 H), 6.65 (d, J = 11.6
Hz, 1 H), 6.82 (s, 2 H), 6.91 (d, J = 8.5 Hz, 1 H), 7.10–7.43
(m, 17 H); 13C NMR (68 MHz, CDCl3): d = –4.1, 18.3, 25.8,
33.6, 71.1, 71.2, 75.3, 105.9, 118.4, 121.1, 127.2, 127.3,
127.4, 127.7, 127.8, 128.1, 128.4, 128.5, 128.6, 130.3,
130.5, 130.7, 133.5, 137.2, 137.8, 137.9, 152.9, 153.4; FAB-
MS: m/z = 642 [M]+; HRMS: m/z [M]+ calcd for C42H46O4Si:
642.3165; found: 642.3162.
MeO
NO2
21
NO2
22
Scheme 7 Decomposition of 20 under basic conditions
(10) Hirooka, Y.; Nitta, M.; Furuta, T.; Kan, T. Synlett 2008,
3234.
(11) Synthesis of sulfone 14: To a stirred solution of iodide 13 (26
mg, 70 mmol) and m-NPTSH 6 (25 mg, 110 mmol) in DMF
(1.0 mL), was added K2CO3 (15 mg, 110 mmol) at room
temperature. After stirring for 90 min, the reaction mixture
was quenched with sat. aq NH4Cl and extracted with
CH2Cl2. The organic layer was washed with sat. aq NH4Cl
and brine, dried over MgSO4, and concentrated in vacuo.
The residue (28 mg) dissolved in CH2Cl2 (1.0 mL) was
treated with m-CPBA (42 mg, 244 mmol) and, after stirring
at 40 °C for 10 h, the reaction mixture was quenched with
sat. aq Na2SO3 and extracted with CH2Cl2. The organic layer
was washed with sat. aq Na2SO3 and sat. aq NaHCO3 and
brine, dried over MgSO4, and concentrated in vacuo. The
residue was purified by preparative TLC to yield sulfone 14
(21 mg, 43 mmol, 62%, 2 steps). Spectral data for 14: IR
(13) (a) Kita, Y.; Toma, T.; Kan, T.; Fukuyama, T. Org. Lett.
2008, 10, 3251. (b) For a similar deprotection of the Ms
group by LDA, see: Ritter, T.; Stanek, K.; Larrosa, I.;
Carreira, E. M. Org. Lett. 2004, 6, 1513.
Synlett 2010, No. 5, 827–829 © Thieme Stuttgart · New York