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Synlett 2010(5): 827-829  
DOI: 10.1055/s-0029-1219386
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Modified Julia-Kocienski Reaction Promoted by Means of m-NPT (Nitro­phenyltetrazole) Sulfone

Yuki Sakai, Kazutada Ikeuchi, Yuji Yamada, Toshiyuki Wakimoto, Toshiyuki Kan*
School of Pharmaceutical Sciences, University of Shizuoka and Global COE Program, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
Fax: +81(54)2645745; e-Mail: kant@u-shizuoka-ken.ac.jp;
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Publication History

Received 1 December 2009
Publication Date:
10 February 2010 (online)

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Abstract

m-Nitrophenyltetrazole sulfone (2) was employed in the Julia-Kocienski reaction. The olefination reaction between 2 and carbonyl compounds proceeded smoothly under Masamune-Roush conditions (DBU and LiCl). These conditions were also applicable to our catechin derivative synthesis. Furthermore, phenolic mesylate was also tolerated in this mild reaction.

Key words

olefination - Julia-Kocienski reaction - sulfone

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Upon treatment of similar p-NPT sulfone derivative 20, under basic conditions, the self-condensation reaction proceeded through Meisenheimer complex 21 to provide 22, as shown in Scheme  [7] .

Scheme 7 Decomposition of 20 under basic conditions

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Synthesis of sulfone 14: To a stirred solution of iodide 13 (26 mg, 70 µmol) and m-NPTSH 6 (25 mg, 110 µmol) in DMF (1.0 mL), was added K2CO3 (15 mg, 110 µmol) 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 (neat): 837, 1101, 1157, 1352, 1539, 2929 cm-¹; ¹H NMR (500 MHz, CDCl3): δ = 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): δ = -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.

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Synthesis of 16: To a stirred solution of sulfone 14 (11 mg, 22 µmol), aldehyde 15 (13 mg, 26 µmol) and LiCl (4.0 mg, 78 µmol) in MeCN (1.0 mL) at 0 ˚C, DBU (12 µL, 78 µmol) 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 µmol, 81%). Spectral data for 16: IR (neat): 839, 1116, 1573, 1693, 2927 cm-¹; ¹H NMR (500 MHz, CDCl3): δ = 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): δ = -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.