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M. Turks et al.
PAPER
25
forded 4.46 g (90%) of (–)-18; Rf = 0.20 (PE–EtOAc, 94:6); [a]D
–10 (c = 0.29, CHCl3).
stirred at 20 °C for 20 min. The flask was cooled to –196 °C with
liquid N2 and SO2 (approx. 3 mL) was condensed to the frozen mix-
ture. It was allowed to melt at –78 °C. Following the dropwise ad-
dition of a solution of diene (–)-14 (63 mg, 0.2 mmol) and (–)-19
(211 mg, 0.4 mmol, 2.0 equiv) in toluene (0.25 mL), the mixture
was stirred at –78 °C for 24 h. SO2 was evaporated at –78 °C in vac-
uo for 2 h, then a premixed solution of abs. MeOH (0.27 mL), Et3N
(0.04 mL, 0.2 mmol, 1.1 equiv), and TMSOTf (0.04 mL, 0.2 mmol,
1.3 equiv) were added and the mixture was stirred for 3 h, allowing
it to warm up to –40 °C. The mixture was poured into ice cold aq
soln of NaHCO3 (5 mL). The aqueous layer was extracted with
CH2Cl2 (5 × mL). The combined extracts were washed again with
sat. aq soln of NaHCO3 (5 mL), H2O (5 mL), and brine (5 mL), then
dried (MgSO4). Solvent evaporation, FC (PE–EtOAc) gave 116 mg
(78%) of (+)-20; colorless oil; Rf = 0.29 (PE–EtOAc, 9:1);
[a]D25 +18 (c = 0.23, CHCl3).
IR (film): 3455, 3070, 2960, 2930, 1635, 1455, 1425, 1375, 1250,
1110, 1085, 1040, 970, 835, 700, 630 cm–1.
1H NMR (CDCl3): d = 0.20, 0.22 [2 s, 6 H, Si(CH3)2Ph], 0.81 (d, J4,4-
Me = 6.8 Hz, 3 H, 4-CCH3), 0.94 (t, J1,2 = 7.4 Hz, 3 H, 1-CH3), 1.28–
1.36 (m, 1 H, 2-CHa), 1.40 (d, J2¢,1¢ = 6.8 Hz, 3 H, 2¢-CH3), 1.52 (s,
2 H, CH2SiMe2Ph), 1.59–1.63 (m, 1 H, 2-CHb), 1.75–1.84 (m, 1 H,
4-CH), 1.95 (d, J6,5 = 6.8 Hz, 2 H, 6-CH2), 2.38 (d, JOH,3 = 4.3 Hz, 1
H, 3-OH), 3.21–3.25 (m, 1 H, 3-CH), 3.61 (m, 1 H, 5-CH), 4.44 (q,
J
1¢,2¢ = 6.8 Hz, 1 H, 1¢-CH), 4.50, 4.61 (2 s, 1 H, 8-CH2), 7.23–7.35
(m, 8 H, CHarom), 7.41–7.43 (m, 2 H, CHarom).
13C NMR (CDCl3): d = –3.3, –3.0 [q, Si(CH3)2Ph], 9.7 (q, C-1), 12.8
(q, 4-CCH3), 23.2 (q, C-2¢), 27.7 (CH2SiMe2Ph), 36.9 (t, C-2), 40.8
(t, C-6), 41.0 (d, C-4), 75.3 (d, C-3), 75.7 (d, C-1¢), 77.9 (d, C-5),
110.9 (t, C-8), 126.5 (d, CHarom), 127.2 (d, CHarom), 127.7 (d,
CHarom), 128.1 (d, CHarom), 128.9 (d, CHarom), 133.6 (d, CHarom),
139.3 (s, Carom), 143.3 (s, Carom), 143.9 (s, C-7).
IR (film): 3065, 3030, 2960, 2930, 2855, 1730, 1450, 1255, 1085,
1065, 1025, 835, 760, 700 cm–1.
1H NMR (CDCl3): d = –0.03, 0.02 [2 s, 6 H, Si(CH3)2C(CH3)3], 0.75
(d, J4,4-Me = 7.0 Hz, 3 H, 4-CCH3), 0.84 [s, 9 H, Si(CH3)2C(CH3)3],
0.88 (dd, J1,2-cis = 7.0 Hz, J1,2-trans = 7.7 Hz, 3 H, 1-CH3), 1.06 (d,
J3¢,3¢-Me = 7.0 Hz, 3 H, 3¢-CH3), 1.31, 1.34 (2 d, J2¢¢,1¢¢/2¢¢¢,1¢¢¢ = 6.4 Hz,
6 H, 2¢¢-CH3, 2¢¢¢-CH3), 1.37–1.47 (m, 2 H, 2-CH2), 1.49 (d,
ESI-HRMS: m/z calcd for C26H38O2Si + Na+: 433.2533; found:
433.2549.
(–)-(3R,4R,5S,1¢S)-4-Methyl-7-(dimethylphenylsilyl)methyl-3-
[(tert-butyldimethylsilyl)oxy]-5-[(1S)-1-phenylethoxy]oct-7-ene
[(–)-19]
J6¢,5¢ = 6.4 Hz, 3 H, 6¢-CH3), 1.82–1.94 (m, 5 H, 6-CH2, 4-CH, 1¢-
CH2), 2.83 (m, 1 H, 3¢-CH), 3.36–3.45 (m, 2 H, 5-CH, 2¢-CH), 3.65–
3.69 (m, 1 H, 3-CH), 4.34–4.41 (m, 2 H, 1¢¢-CH, 1¢¢¢-CH), 4.60 (s, 2
H, 8-CH2), 5.14 (q, J5¢,6¢ = 6.4 Hz, 1 H, 5¢-CH), 7.03–7.10 (m, 5 H,
CHarom), 7.19–7.27 (m, 5 H, CHarom), 7.40–7.44 (m, 2 H, CHarom),
7.58–7.62 (m, 1 H, CHarom), 7.96–7.98 (m, 2 H, CHarom).
Et3N (0.35 mL, 2.5 mmol, 2.2 equiv) was added to a solution of
(–)-18 (468 mg, 1.14 mmol) in CH2Cl2 (16 mL). The mixture was
cooled to –15 °C and treated with TBSOTf (0.32 mL, 1.3 mmol, 1.2
equiv) and allowed to reach 20 °C over 5 h. It was poured into sat.
aq soln of NaHCO3 (10 mL). Extraction with CH2Cl2 (3 × 10 mL),
washing the combined organic layers with brine (10 mL), drying
(MgSO4), evaporation, and FC (pentane–CH2Cl2, 4:1) afforded 514
mg (86%) of (–)-19; colorless oil; Rf = 0.37 (PE–CH2Cl2, 8:2);
[a]D25 –17 (c = 0.54, CHCl3).
13C NMR (CDCl3): d = –4.2, –4.1 [2 q, Si(CH3)2C(CH3)3], 9.9 (q, C-
1), 10.6 (q, 4-CCH3), 11.3 (q, C-6¢), 11.8 (q, 3¢-CCH3), 18.4 [s,
Si(CH3)2C(CH3)3], 24.2 (q, C-2¢¢, C-2¢¢¢), 25.8 (t, C-2), 26.2 [q,
Si(CH3)2C(CH3)3], 37.7 (t, C-1¢), 38.6 (t, C-6), 39.8 (d, C-3¢), 41.6
(d, C-4), 74.3 (d, C-3), 75.3 (d, C-2¢), 75.3, 75.4 (2 d, C-1¢¢, C-1¢¢¢),
76.3 (d, C-5), 112.3 (d, C-5¢), 114.5 (t, C-8), 126.9 (d, CHarom),
127.1 (d, CHarom), 127.3 (d, CHarom), 128.2 (d, CHarom), 128.3 (d,
CHarom), 128.7 (d, CHarom), 129.9 (s, Carom), 130.3 (d, CHarom), 144.0
(s, Carom), 144.9 (s, C-7), 150.7 (s, C-4¢), 164.4 [s, OC(O)Ph].
IR (film): 3065, 3030, 2960, 2930, 2860, 1730, 1600, 1450, 1370,
1255, 1165, 1085, 1070, 1025, 1010, 940, 835, 770, 700 cm–1.
1H NMR (CDCl3): d = –4.4, –4.1 [2 s, Si(CH3)2C(CH3)3], 0.35 [s, 6
H, Si(CH3)2Ph], 0.92 [d, J4,4-Me = 7.1 Hz, 3 H, 4-CH(CH3)], 0.96 [s,
9 H, SiMe2C(CH3)3], 1.01 (t, J1,2 = 7.1 Hz, 3 H, 1-CH3), 1.48 (d,
(4S,5S,9S,10R,11R,2Z)-11-Hydroxy-4,10-dimethyl-7-methyl-
ene-5,9-bis[(S)-1-phenylethoxy]tridec-2-en-3-yl benzoate
[(–)-21]
J
2¢,1¢ = 6.2 Hz, 3 H, 2¢-CH3), 1.64–1.50 (m, 2 H, 2-CH2), 1.79, 1.70
(2 d, AB-system, Jgem = 13.6 Hz, 2 H, 7-CH2SiMe2Ph), 2.02 (dd,
J6a,b = 14.4 Hz, J6b,5 = 8.3 Hz, 1 H, 6-CHb), 2.09 (dd, J6a,b = 14.4 Hz,
J6a,5 = 4.1 Hz, 1 H, 6-CHa), 2.11 (m, 1 H, 4-CH), 3.67 (dt, J5,6a = 4.1
Hz, J5,6b = 8.3 Hz, 1 H, 5-CH), 3.75 (dt, J3,4 = 5.9 Hz, J3.2 = 5.3 Hz,
1 H, 3-CH), 4.54 (q, J1¢,2¢ = 6.5 Hz, 1 H, 1¢-CH), 4.59, 4.66 (2 s, 2 H,
8-CH2), 7.30–7.45 (m, 8 H, CHarom), 7.54-7.57 (m, 2 H, CHarom).
13C NMR (CDCl3): d = –4.4, –4.1 [2 q, Si(C(CH3)3)(CH3)2], –2.9,
–2.8 [2 q, Si(CH3)2Ph], 9.1 (q, C-1), 10.4 (q, 4-CCH3), 18.2 [s,
Si(C(CH3)3)(CH3)2], 24.2 (q, C-2¢), 26.0 (t, CH2SiMe2Ph), 26.2 [3
q, Si(C(CH3)3)(CH3)2], 39.8 (t, C-2), 40.1 (t, C-6), 74.1 (d, C-3),
75.0 (d, C-1¢), 76.0 (d, C-5), 110.5 (t, C-8), 126.8 (d, CHarom), 127.1
(d, CHarom) 127.7 (d, CHarom), 128.1 (d, CHarom), 128.9 (d, CHarom),
133.7 (d, CHarom), 139.3 (s, Carom), 144.1 (s, Carom), 144.2 (s, C-7).
Compound (+)-20 (25 mg, 0.035 mmol) was dissolved in MeCN
(0.6 mL) at 20 °C, HF·pyridine 53 mg (65–70%, 0.345 mmol, 9.8
equiv) was added and the mixture was stirred overnight. The sol-
vents were evaporated in vacuo and the residue was dissolved in
CH2Cl2 (2 mL) and poured into sat. aq soln of NaHCO3 (2 mL). The
aqueous phase was extracted with CH2Cl2 (2 × 2 mL). The com-
bined organic extracts were dried (MgSO4) and the solvent evapo-
rated in vacuo; FC (PE–EtOAc, 9:1); yield: 18 mg (86%); colorless
oil; Rf = 0.19 (PE–EtOAc, 9:1); [a]D25 –22 (c = 0.66, CHCl3).
IR (film): 3540, 3030, 2975, 2930, 1730, 1645, 1600, 1495, 1455,
1370, 1260, 1090, 1030 cm–1.
1H NMR (CDCl3): d = 0.78 (d, J4,4-Me = 6.8 Hz, 3 H, 4-CCH3), 0.95
(t, J1,2 = 7.4 Hz, 3 H, 1-CH3), 1.00 (d, J3¢,3¢-Me = 7.4 Hz, 3 H, 3¢-
CCH3), 1.25–1.31 (m, 1 H, 2-CH2), 1.32 (d, J2¢¢,1¢¢ = 6.8 Hz, 3 H, 2¢¢-
CH3), 1.38 (d, J2¢¢¢,1¢¢¢ = 6.2 Hz, 3 H, 2¢¢¢-CH3), 1.44 (d, J6¢,5¢ = 6.8 Hz,
3 H, 6¢-CH3), 1.45–1.65 (m, 3 H, 2-CH2, 6-CH2, 1¢-CH2), 1.72–1.84
(m, 3 H, 4-CH, 6-CH2, 1¢-CH2), 2.67 (d, JOH,3 = 4.3 Hz, 1 H, 3-OH),
2.75 (dq, J = 6.9 Hz, J3¢,2¢ = 3.1 Hz, 1 H, 3¢-CH), 3.09 (ddt,
J3,OH = 4.3, 2.6, 8.2 Hz, 1 H, 3-CH), 3.25 (ddd, J2¢,1¢-trans = 10.5 Hz,
MALDI-HRMS: m/z calcd for C32H52O2Si2 + Na+: 547.3404; found:
547.3428.
Anal. Calcd for C32H52O2Si2 (525.93): C, 73.22; H, 9.98. Found: C,
73.26; H, 10.02.
(4S,5S,9S,10S,11R,Z)-11-(tert-Butyldimethylsilyloxy)-4,10-di-
methyl-7-methylene-5,9-bis[(S)-1-phenylethoxy]tridec-2-en-3-
yl benzoate [(+)-20]
A dry two-necked flask attached to a vacuum line and an argon-sup-
ply via a three way tap was charged with toluene (0.7 mL), Tf2NH
(0.115 mL, 0.057 mmol, 0.3 equiv, 0.5 M in CH2Cl2) and allyltri-
methylsilane (0.01 mL, 0.057 mmol, 0.3 equiv). The mixture was
J2¢,3¢ = 3.1 Hz, J2¢,3¢ = 3.1 Hz, J2¢,1¢-cis = 2.5 Hz, 1 H, 2¢-CH), 3.48
(ddd, J = 9.9, 3.1, 3.7 Hz, 1 H, 5-CH), 4.29 (q, J1¢¢,2¢¢ = 6.8 Hz, 1 H,
1¢¢-CH), 4.42 (q, J1¢¢¢,2¢¢¢ = 6.2 Hz, 1 H, 1¢¢¢-CH), 4.80, 4.79 (2 s, 2 H,
8-CH2), 4.95 (q, J5¢,6¢ = 6.8 Hz, 1 H, 5¢-CH), 6.99–7.10 (m, 5 H,
Synthesis 2009, No. 7, 1065–1074 © Thieme Stuttgart · New York