Synlett 2003(5): 0729-0731
DOI: 10.1055/s-2003-38356
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Vinylsulfone Derivatives of Sugars: An Easy Preparation of (2R,3S,4E)-5-Benzenesulfonyl-2,3-iso-propylidene-dioxy-pent-4-en-1-yl-tosylate

David Díez*, M. Templo Beneitez, Isidro S. Marcos, N. M. Garrido, P. Basabe, Julio G. Urones
Dpto. de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1-5, 37008 Salamanca, Spain
Fax: +34(923)294574; e-Mail: ddm@usal.es;
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Publikationsverlauf

Received 23 December 2002
Publikationsdatum:
28. März 2003 (online)

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Abstract

A two-step procedure for the synthesis of (2R,3S,4E)-5-benzenesulfonyl-2,3-isopropylidene-dioxypent-4-en-1-yl-tosylate is described. The method involves the addition of lithio(phenylsulfonyl)methane to 2,3-O-iso-propylidene-d-erythronolactol and treatment of the resulting diols with tosyl chloride.

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To a solution of PhSO2Me (4.10 g, 26.3 mmol) in dry THF (40 mL), was added drop wise a solution 1.6 M of n-BuLi (16.4 mL, 26.3 mmol) at 0 °C and stirred under argon for 10 min, cooled down to -78 °C and cannulated to a solution of lactol 6 (2.80 g, 17.5 mmol) in 60 mL of THF. After 30 min the cooling bath was removed and stirring was continued at r.t. for 2 h, quenched with sat. NH4Cl solution and extracted with EtOAc. The combined organic layers were washed with water and brine and dried over Na2SO4. After concentration the residue was purified by chromatography (n-hexane/EtOAc: 7/3) to give a mixture (75/25) of 7 and 8 [12] (5.3 g, 95%). This mixture of 7 and 8 (5.3 g, 16.8 mmol) was added to a solution of THF washed NaH (2.7 g, 67.1 mmol) in dry THF (20 mL) at 0 °C and stirred at that temperature for 40 min, cooling down to -78 °C and then added a mixture of TsCl (19.2 g, 100.6 mmol) in dry THF (30 mL). The mixture was stirred for 15 min, quenched with 2 N HCl until neutral pH and extracted with EtOAc. The combined organic layers were washed with H2O and brine and dried over Na2SO4. After concentration the residue was purified by chromatography (n-hexane/EtOAc: 8/2) to give a mixture of olefins 3 (5.1 g, 68%) and 11 (1.7 g, 22%) and tetrahydrofurans 9 (150 mg, 3%), and 10 (100 mg, 2%). Spectroscopic data for compounds 3, 9 and 10, see ref. [3] . Spectroscopic data for compound 11: [α] d 20 = +184.0 (c 1.30, CHCl3). IR (film): ν = 1456, 1364, 1308, 1177, 988 cm-1. 1H NMR (CDCl3, 200 MHz): δ = 7.95-7.31 (9 H, m,
-Ar), 6.34-6.20 (2 H, m, H-4, H-5), 5.72 (1 H, dd, J = 5.4 and 7.4 Hz, H-3), 4.62 (1 H, ddd, J = 3.8, 4.8 and 7.4 Hz, H-2), 4.11 (1 H, dd, J = 3.8 and 10.6 Hz, HA-5), 3.94 (1 H, dd, J = 4.8 and 10.6 Hz, HB-1), 2.44 (3 H, s, CH3-Ts), 1.44 (CH3-acetonide), 1.36 (CH3-acetonide). 13C NMR (CDCl3, 50.3 MHz): δ = 145.2 (C-ipso, -Ts), 141.5 (CH-4), 140.1 (C-ipso, -SO2Ph), 134.3 (CH-5), 132.8 (C-ipso, -Ts), 132.1 (CH-para, -SO2Ph), 130.1 (2 CH-meta, -Ts), 129.8 (2 CH-ortho, -Ts), 128.2 (2 CH-meta, -SO2Ph), 127.7 (2 CH-ortho,
-SO2Ph), 110.5 (C-acetonide), 76.5 (CH-3), 72.8 (CH-2), 68.4 (CH2-5), 27.3 (CH3-acetonide), 25.2 (CH3-acetonide), 21.9 (CH3-Ts). MS (EI): m/z (%) = 452 (5) [M+], 437(25), 267 (10), 238 (20), 209 (30), 155 (50), 125 (60), 91 (100). HRMS (EI): m/z calcd for C21H24O7S2: 452.0963. Found: 452.0964.

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These compounds could be separated by careful chromatography in (n-hexane/EtOAc: 7/3). Spectroscopic data for compound 7: [α] d 20 = -58.3º (c 0.90, CHCl3). IR (film): ν = 3500, 1306, 1142, 1071, 855 cm-1. 1H NMR (CDCl3, 200 MHz): δ = 7.95-7.40 (5 H, m, -Ar), 4.36-4.19 (2 H, m, H-2 and H-3), 3.95-3.74 (3 H, m, H-4, 2 H-1), 3.59 (1 H, d, J = 14.4 Hz, HA-5), 3.19 (1 H, dd, J = 10.0 and 14.4 Hz, HB-5), 1.26 (3 H, s, Me), 1.41 (3 H, s, Me), 13C NMR (CDCl3, 50.3 MHz): δ = 139.5 (C-ipso), 134.2 (CH-para), 129.6 (2CH-meta), 128.2 (2 CH-ortho), 109.0 (C-acetonide), 78.0 (CH-2), 77.4 (CH-3), 65.4 (CH-4), 60.4 (CH2-1), 59.7 (CH2-5), 27.7 (CH3-acetonide), 25.4 (CH3-acetonide). Spectroscopic data for compound 8: [α] d 20 =
-14.2 (c 1.21, CHCl3). IR (film): ν 3500, 1449, 1304, 1217, 1146 cm-1. 1H NMR (CDCl3, 200 MHz): δ = 7.95-7.40 (5 H, m, -Ar), 4.37 (1 H, ddd, J = 2.6, 3.6 and 7.8 Hz, H-4), 4.23 (1 H, m, H-2), 4.12 (1 H, dd, J = 2.2 and 6.6 Hz, H-3), 3.83 (2 H, t, J = 4.0 Hz, H-1), 3.42 (1 H, dd, J = 8.2 and 14.4 Hz, HA-5), 3.30 (1 H, dd, J = 3.6 and 14.4 Hz, HB-5), 1.48 (3 H, s, Me), 1.34 (3 H, s, Me). 13C NMR (CDCl3, 50.3 MHz): δ = 139.9 (C-ipso), 134.1 (CH-para), 129.5 (2 CH-meta), 128.2 (2 CH-ortho), 108.9 (C-acetonide), 78.8 (CH-2), 77.2 (CH-3), 65.0 (CH-4), 60.5 (CH2-1), 60.4 (CH2-5), 26.9 (CH3-acetonide), 25.1 (CH3-acetonide).