C. Bauder
FULL PAPER
(5 mL), water (5 mL), and HCl (10%, 4 mL, to pH = 1). The or-
ganic extract was washed with water (3ϫ 15 mL), brine (8 mL),
dried (Na2SO4), filtered, and concentrated under reduced pressure
to give an orange oil. Purification of this crude material by column
chromatography on silica gel afforded the desired product 14
(160 mg; 70.5%) as a yellow oil and a second less polar product
identified as the unexpected thiol 14a (pale-yellow oil). [α]D = –25.4
(c = 2.5, CHCl3). C27H39NO2S2Si (501.819): calcd. C 64.62, H 7.83,
N 2.79; found C 64.90, H 8.19, N 2.46. 1H NMR (300 MHz,
CDCl3): δ = 7.87 (d, J = 7.7 Hz, 2 H, Bzt), 7.75 (d, J = 8.1 Hz, 2
H, Bzt), 7.41 (td, J = 15.3, J = 1.3 Hz, 1 H, Bzt), 7.35–7.26 (m, 5
H, Ar), 4.52 and 4.46 (AB system, JAB = 11.7, ∆ν = 13 Hz, 2 H,
OCH2Ph), 3.79 (m, 1 H, 11-H), 3.52 (t, J = 6.6 Hz, 2 H, 13-H),
3.46 (m, 1 H, 8a-H), 3.32 (m, 1 H, 8b-H), 2.06 (m, 1 H, 7a-H),
1.77 (m, 1 H, 9-H), 1.73 (m, 2 H, 12-H), 1.62 (m, 1 H, 7b-H), 0.94
(d, J10-9 = 6.8 Hz, 3 H, 10-H), 0.86 (s, 9 H, tBuSi), –0.06 (s, 3 H,
MeSi), –0.04 (s, 3 H, MeSi) ppm. 13C NMR (75 MHz, CDCl3): δ
= 167.3 (Cq arom.), 153.4 (Cq arom.), 138.5 (Cq arom.), 135.2 (Cq
arom.), 128.4 (CH arom.), 127.7 (CH arom.), 127.5 (CH arom.),
126.0 (CH arom.), 124.1 (CH arom.), 121.5 (CH arom.), 121.0 (CH
arom.), 73.0 (OCH2Ph), 72.6 (C-11), 67.4 (C-13), 37.9 (C-9), 32.8
(C-12), 32.1 (C-8), 31.4 (C-7), 25.9 [C(CH3)3Si], 18.1 [C(Me)3Si],
14.8 (C-10), –4.2 (MeSi), –4.5 (MeSi) ppm.
125.5 (CH arom.), 122.3 (CH arom.), 73.0 (OCH2Ph), 72.4 (C-11),
67.1 (C-13), 53.8 (C-7), 37.9 (C-9), 32.6 (C-12), 25.8 [C(CH3)3Si],
24.8 (C-8), 17.9 [C(Me)3Si], 14.8 (C-10), –4.4 (MeSi), –4.6 (MeSi)
ppm.
2-(Methylthio)benzo[d]thiazole (16): Synthesized according the lit-
erature.[27] Amber solid. 1H NMR (300 MHz, CDCl3): δ = 7.87 (d,
J = 7.7 Hz, 1 H), 7.75 (d, J = 8.1 Hz, 1 H), 7.71 (td, J = 7.1, 1.3 Hz,
1 H), 7.28 (td, J = 7.9, 1.3 Hz, 1 H), 2.79 (s, 3 H, Me) ppm. 13C
NMR (75 MHz, CDCl3): δ = 168.1 (Cq arom.), 153.3 (Cq arom.),
135.1 (Cq arom.), 126.1 (CH arom.), 124.1 (CH arom.), 121.4 (CH
arom.), 120.9 (CH arom.), 15.9 (MeS) ppm.
Preparation of Compound 17: A solution of LHMDS (1 in THF,
0.55 mL, 2.3 equiv.) was added dropwise at –72 °C to a solution
of benzothiazolyl sulfone 15 (126 mg, 0.236 mmol) and aldehyde 4
(58 mg, 1.7 equiv.) in THF (8 mL). The resulting yellow solution
was stirred from –72 °C to –10 °C for 2 h, then diluted with EtOAc
(10 mL), and the reaction quenched with satd. aq. NH4Cl (4 mL)
followed by water (4 mL) and aq. HCl (10%, 1 mL) until pH = 4.
The organic layer was washed with water (2ϫ 10 mL), brine and
dried with Na2SO4. Evaporation of the solvents under reduced
pressure gave an orange oil, which was purified by column
chromatography on silica gel (EtOAc/cyclohexane, 3:7) to afford a
light-yellow liquid of 17 (105 mg, 81.3%) as a mixture of (E)/(Z)
olefins (ratio 1:1). The two isomers were easily separated on a pre-
parative thin layer plate impregnated with silver nitrate in MeCN
(1 g/5 mL); elution with EtOAc/cyclohexane (5:95; products visual-
ized with KMnO4) afforded the (E) olefin (Rf = 0.6) and (Z) olefin
(Rf = 0.4). Each olefin was assigned by 2D NMR spectroscopic
analyses at high field (600 MHz).
(–)-[(3S,4S)-1-(Benzyloxy)-4-methyl-6-(methylthio)hex-3-yloxy]-
(tert-butyl)dimethylsilane (14a): Yellow oil. [α]D = –21 (c = 1,
CHCl3). C21H38O2SSi (382.675): calcd. C 65.91, H 10.01; found C
1
65.52, H 10.20. H NMR (300 MHz, CDCl3): δ = 7.35–7.26 (m, 5
H, Ar), 4.52 and 4.46 (AB system, JAB = 11.9 Hz, ∆ν = 13 Hz, 2
H, OCH2Ph), 3.93–3.88 (m, 1 H, 11-H), 3.50 (t, J13-2 = 6.6 Hz, 1
H, 13-H), 2.48 (AB part of an ABX system, JAB = 12.5 Hz, JAX
=
(–)-(3S,4S,6E,9R,10E)-1-(Benzyloxy)-3,9-bis(tert-butyldimethylsil-
yloxy)-4-methyldodeca-6,10-diene [17, (E) Isomer]: Light-yellow oil.
9.0 Hz, JBX = 5.1 Hz, ∆ν = 95 Hz, 2 H, 8-H), 2.06 (s, 3 H, MeS),
1.85–1.64 (m, 3 H, 9-H and 12-H), 0.96 (d, J10-9 = 6.8 Hz, 3 H, 10-
H), 0.89 (s, 9 H, tBuSi), 0.06 (s, 3 H, MeSi), 0.05 (s, 3 H, MeSi)
ppm. 13C NMR (75 MHz, CDCl3): δ = 138.5 (Cq arom.), 128.4
(CH arom.), 127.6 (CH arom.), 127.5 (CH arom.), 73.0 (OCH2Ph),
71.5 (C-11), 67.4 (C-13), 38.0 (C-9), 37.7 (C-8), 33.6 (C-12), 25.9
[C(CH3)3Si], 18.1 [C(Me)3Si], 15.9 (MeS), 14.1 (C-10), –4.3 (MeSi),
–4.4 (MeSi) ppm.
[α]D
C32H58NaO3Si2 [M + Na]+ 569.381; found 569.374. 1H NMR
(600 MHz, CDCl3): δ = 7.36–7.26 (m, 5 H, Ph), 5.57 (dq, J2-3
= –11.9 (c = 0.66, CHCl3). MS (ESI): calcd. for
=
15.3, J2-1 = 6.4 Hz, 1 H, 2-H), 5.33 (ddq, J3-2 = 15.3, J3-4 = 6.4,
J3-1 = 1.5 Hz, 1 H, 3-H), 5.4–5.3 (m, 2 H, 6-H and 7-H), 4.53 and
4.49 (AB system, JAB = 6, ∆ν = 10.7 Hz, 2 H, OCH2Ph), 4.02 (td,
J4-5 = J4-3 = 6.4 Hz, 1 H, 4-H), 3.75 (dt, J = 7.9, 4.0 Hz, 1 H, 11-
H), 3.49 (m, 2 H, 13-H), 2.24 (m, 1 H, 8a-H), 2.15 (m, 2 H, 5-H),
1.73 (m, 2 H, 12-H), 1.68 (d, J1-2 = 6.6 Hz, 3 H, 1-H), 1.67 (m, 1
H, 8b-H), 1.54 (m, 1 H, 9-H), 0.90 (s, 9 H, tBuSi), 0.89 (s, 9 H,
tBuSi), 0.82 (d, J10-9 = 6.6 Hz, 3 H, 10-H), –0.054 (s, 3 H, MeSi),
–0.051 (s, 3 H, MeSi), –0.04 (s, 3 H, MeSi), –0.03 (s, 3 H, MeSi)
ppm. 13C NMR (75 MHz, CDCl3): δ = 138.6 (Cq arom.), 134.5 (C-
3), 131.7 (C-6 or C-7), 128.3 (CH arom.), 127.7 (CH arom.), 127.6
(CH arom.), 127.5 (C-6 or C-7), 124.9 (C-2), 73.8 (C-4), 72.9
(OCH2Ph), 72.8 (C-11), 67.6 (C-13), 42.0 (C-5), 39.0 (C-9), 35.1
(C-8), 33.0 (C-12), 29.7 (fatty grease CH2), 25.9 [C(CH3)3Si], 18.3
[C(Me)3Si], 18.1 [C(Me)3Si], 17.6 (C-1), 14.4 (C-10), –4.27 (MeSi),
–4.33 (MeSi), –4.5 (MeSi), –4.7 (MeSi) ppm.
(–)-2-[(3S,4S)-6-(Benzyloxy)-4-(tert-butyldimethylsilyloxy)-3-meth-
ylhexylsulfonyl]benzo[d]thiazole (15): A solution of ammonium
molybdate (7 mg, 4.2% mol-equiv.) in water (0.3 mL) and hydrogen
peroxide (30% in water, 0.2 mL, 13 equiv.) was added dropwise to
a precooled (0 °C) solution of the previous sulfide 14 (67 mg,
0.133 mmol) in EtOH (1 mL). The yellow mixture was stirred at
room temp. for 21 h, then EtOAc (5 mL) and satd. aq. NaCl (1 mL)
were added before evoparation of the solvents under reduced pres-
sure. Water (5 mL) and EtOAc (10 mL) were added to the resulting
solid. The organic layer was washed with water (3ϫ 5 mL), brine
(2 mL), dried (Na2SO4), filtered, and concentrated under reduced
pressure to leave a yellow liquid. Purification by column
chromatography on silica gel (EtOAc/cyclohexane, 3:7) furnished
15 (48 mg, 67.3%) as a colorless oil. [α]D = –15.1 (c = 1.55, CHCl3).
C27H39NO4S2Si (533.818): calcd. C 60.75, H 7.36, N 2.62; found C
(–)-(3S,4S,6Z,9R,10E)-1-(Benzyloxy)-3,9-bis(tert-butyldimethylsil-
yloxy)-4-methyldodeca-6,10-diene [17, (Z) Isomer]: Yellow oil. [α]D
= –15 (c = 0.42, CHCl3). MS (ESI): calcd. for C32H58NaO3Si2 [M
+ Na]+ 569.381; found 569.4. 1H NMR (600 MHz, CDCl3): δ =
7.36–7.26 (m, 5 H, Ph), 5.56 (dq, J2-3 = 15.2, J2-1 = 6.4 Hz, 1 H,
1
61.06, H 7.66, N 2.19. H NMR (300 MHz, CDCl3): δ = 8.21 (d,
J = 9.1 Hz, 1 H, Bzt), 8.01 (d, J = 7.3 Hz, 1 H, Bzt), 7.66–7.55 (m,
2 H, Bzt), 7.36–7.27 (m, 5 H, Ph), 4.48 and 4.42 (AB system, JAB
= 11.7, ∆ν = 14.7 Hz, 2 H, OCH2Ph), 3.77 (m, 1 H, 11-H), 3.54 (t, 2-H), 5.5–5.40 (m, 3 H, 3-H, 6-H and 7-H), 4.53 and 4.49 (AB
J = 7.8 Hz, 7-H), 3.46 (t, J = 6.5 Hz, 13-H), 2.04 (m, 1 H, 8a-H), system, JAB = 6, ∆ν = 11.1 Hz, 2 H, OCH2Ph), 4.06 (td, J4-5
=
1.76–1.55 (m, 4 H, 8b-H, 9-H and 12-H), 0.86 (d, J10-9 = 6.6 Hz, 3
H, 10-H), 0.74 (s, 9 H, tBuSi), –0.02 (s, 3 H, MeSi), –0.05 (s, 3 H,
J4-3 = 6.5 Hz, 1 H, 4-H), 3.77 (dt, J = 8.0, 4.2 Hz, 1 H, 11-H), 3.53
(m, 2 H, 13-H), 2.23 (m, 1 H, 5a-H), 2.15 (m, 2 H, 5b-H and 8a-
MeSi) ppm. 13C NMR (75 MHz, CDCl3): δ = 165.8 (Cq arom.), H), 1.84 (m, 1 H, 8b-H), 1.74 (m, 1 H, 12a-H), 1.68 (d, J1-2
=
152.8 (Cq arom.), 138.4 (Cq arom.), 136.8 (Cq arom.), 128.4 (CH 6.6 Hz, 3 H, 1-H), 1.66 (m, 1 H, 12b-H), 1.54 (m, 1 H, 9-H), 0.91
arom.), 128.0 (CH arom.), 127.7 (CH arom.), 127.6 (CH arom.), (s, 9 H, tBuSi), 0.90 (s, 9 H, tBuSi), 0.84 (d, J10-9 = 6.9 Hz, 3 H,
6214
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Eur. J. Org. Chem. 2010, 6207–6216