7
General Procedure for β-Hydroxysulfinic Acids 5: To a stirred solution of the corresponding β-sultone 1 in Et2O (10 mL/mmol) a solution of LiAlH4 (1 M in THF, 0.5 equiv) in Et2O (2.5 mL/mmol 1) was added dropwise at r.t. After 10 min the reaction mixture was quenched with ice and HCl (1 M, 1 mL/mmol 1). Et2O was removed in a stream of N2 and the remaining aqueous solution was filtrated over Amberlite IR-120 (acidic form). The resin was washed with H2O until the eluate was no longer acidic. Concentration in vacuo yielded the corresponding sulfinic acids 5. For 1d and 1e the quenched, acidified reaction mixture was not purified by ion-exchange resin, but extracted with CHCl3 (4 ×). In the case of 1d quenching the reaction mixture with H2O followed by extraction with CHCl3 yielded the corresponding γ-sultine 6.
General Procedure for γ,γ-Dichloroallylsulfonic Acids 7: The corresponding β-sultone 1 was dissolved in EtOH (1 mL/5 mg 1) and Pd (10% on activated charcoal, 0.02 equiv) was added. The suspension was stirred for 21 h under a positive pressure (1 atm) of H2. The reaction mixture was then filtrated over Celite, repeatedly washed with EtOH and the filtrate was concentrated in vacuo. H2O (1 mL/5 mg) was added to the dark oily residue and the solids were removed by filtration. Concentration of the colorless filtrate yielded the corresponding sulfonic acids 7.
General Procedure for γ-Monochloroallylsulfonic Acids 11: To a stirred solution of the corresponding β-sultone 10 in THF (1 mL/7 mg) AcOH (5 equiv) was added, followed by Zn dust (5 equiv). The flask was subsequently closed and stirring was continued at 60 °C for 12 h. The reaction mixture was filtrated over Celite and the filter cake was washed with EtOH. The filtrate was concentrated in vacuo and the residue was dissolved in H2O. To remove unreacted sultone the aqueous layer was washed with MTBE (2 × 25 mL). To remove Zn salts the aqueous layer was subsequently filtrated over Amberlite IR-120 (acidic form) and the resin was washed with H2O until the eluate was no longer acidic. Concentration in vacuo yielded the corresponding monochloroallylsulfonic acids 11.
10 For a previous X-ray crystal structure analysis of a γ-sultine, see ref. 8c.
12 Each unit cell contains two independent molecules with the same configuration, but with slightly different conformations. The second conformer not depicted in Figure
[1]
shows a stronger distortion of the envelope resembling a half-chair conformation. Supplementary crystallographic data have been deposited with the Cambridge Crystallographic Data Centre as deposition 676601. This material is available free of charge via the In-ternet at http://www.ccdc.cam.ac.uk/products/csd/request/.
15 Analytical data for sulfinic acids 5: 5a: 1H NMR (300 MHz, D2O): δ = 4.66 (d, J = 1.6 Hz, 1 H, CHOH), 3.19 (dq, J = 1.6, 7.2 Hz, 1 H, CHS), 1.36 (dd, J = 7.2 Hz, 3 H, Me). 13C NMR (75 MHz, D2O): δ = 101.8 (CCl3), 76.9 (CHCCl3), 61.6 (CSO2H), 6.3 (Me). IR (ATR): 2970, 2497, 1454, 1365, 1216 cm-1. [α]D
23.6 +37.68 ± 0.12 (c = 1.25, H2O; sample with ee = 87%). 5b: 1H NMR (300 MHz, D2O): δ = 4.57 (d, J = 1.3 Hz, 1 H, CHOH), 2.91 (ddd, J = 1.3, 4.4, 9.3 Hz, 1 H, CHS), 2.00 (tdd, J = 3.4, 7.8, 15.6 Hz, 1 H, CHHCHS), 1.60 (tdd, J = 7.5, 9.3, 15.6 Hz, 1 H, CHHCHS), 0.96 (dd, J = 7.5, 7.8 Hz, 3 H, Me). 13C NMR (75 MHz, D2O): δ = 102.2 (CCl3), 75.8 (CHCCl3), 67.1 (CSO2H), 16.6 (CH2CH3), 11.9 (Me). IR (ATR): 3356, 2970, 1365, 1228 cm-1. [α]D
27.9 +53.18 ± 0.12 (c = 0.6, H2O; sample with ee >99%). 5c: 1H NMR (300 MHz, D2O): δ = 4.72 (m, 1 H, CHOH), 2.94-3.06 (m, 1 H, CHS), 1.94-2.14 (m, 1 H, CHHCHS), 1.41-1.81 (m, 3 H, CHHCHS, CH
2CH3), 0.83-1.01 (m, 3 H, Me). 13C NMR (75 MHz, D2O): δ = 102.4 (CCl3), 76.1 (CHCCl3), 65.5 (CSO2H), 25.1 (CH2Et), 20.8 (CH2
CH2CH3), 13.4 (Me). IR (ATR): 3402, 1352, 1139 cm-1. [α]D
24.0 +30.32 ± 0.93 (c = 0.55, H2O; sample with ee = 85%). 5d: 1H NMR (300 MHz, CDCl3): δ = 5.02 (m, 1 H, CHOH), 2.74-3.82 (m, 2 H, CHHCl, CHS), 2.54-3.61 (m, 1 H, CHHCl), 2.74-2.86 (m, 1 H, CHHCHS), 2.28-2.41 (m, 1 H, CHHCHS). 13C NMR (75 MHz, CDCl3): δ = 101.5 (CCl3), 77.2 (CHCCl3), 61.7 (CSO2H), 42.2 (CH2Cl), 26.0 (CH2CHS). IR (ATR): 3386, 2923, 1111 cm-1. [α]D
22.0 +31.93 ± 0.49 (c = 1.00, CHCl3; sample with ee = 96%). 5e: 1H NMR (300 MHz, CDCl3): δ = 7.25-7.35 (m, 5 H, CHPh), 5.23 (br, 2 H, OH, SO2H), 5.15 (m, 1 H, CHOH), 2.60-3.78 (m, 2 H, CHHPh, CHS), 3.12 (dd, J = 11.5, 15.3 Hz, 1 H, CHHPh). 13C NMR (75 MHz, CDCl3): δ = 129.2 (2 × CPh), 128.8 (2 × CPh), 128.7 (CPh,q), 127.2 (CPh), 101.8 (CCl3), 76.0 (CHCCl3), 65.5 (CSO2H), 29.7 (CH2Ph). IR (ATR): 3383, 1496, 1454, 1106 cm-1. [α]D
21.5 +41.51 ± 0.44 (c = 1.15, CHCl3; sample with ee = 99%). γ-Sultine 6: HRMS (EI): m/z [M]+ calcd for C5H7O3SCl3: 251.9176; found: 251.9175. Anal. Calcd for C5H7Cl3O3S: C, 23.69; H, 2.78. Found: C, 23.90; H, 2.88. (2S)-6: R
f
0.39 (EtOAc-cyclohexane, 1:1); mp 123.5-124.4 °C. 1H NMR (300 MHz, CDCl3): δ = 4.88 (ddd, J = 4.0, 8.7, 12.8 Hz, 1 H, CHHO), 4.70 (m, 1 H, CHOH), 4.48-4.57 (m, 1 H, CHHO), 3.76 (d, J = 4.4 Hz, 1 H, OH), 3.72 (ddd, J = 4.4, 8.4, 10.6 Hz, 1 H, CHS), 2.76-2.90 (m, 1 H, CH2CHHCH), 2.39-2.49 (m, 1 H, CH2CHHCH). 13C NMR (75 MHz, CDCl3): δ = 101.4 (CCl3), 78.6 (Cl3CCHO), 76.0 (CH2
CH2O), 68.5 (CHS), 24.1 (CH2
CH2CH). IR (ATR): 3292, 1082, 1075 cm-1. [α]D
23.9 -92.33 ± 0.21 (c = 1.05, CHCl3; sample with ee = 96%). (2R)-6: R
f
: 0.50 (EtOAc-cyclohexane, 1:1); mp 108.1-110.0 °C. 1H NMR (300 MHz, CDCl3): δ = 4.89 (dt, J = 7.2, 8.4 Hz, 1 H, CHHO), 4.70-4.78 (m, 1 H, CHHO), 4.58 (m, 1 H, CHOH), 3.78-3.85 (m, 1 H, CHS), 3.38 (br, 1 H, OH), 2.52-2.73 (m, 2 H, CH2CH
2CH). 13C NMR (75 MHz, CDCl3): δ = 102.0 (CCl3), 78.1 (Cl3CCHO), 77.2 (CHS), 75.7 (CH2
CH2O), 24.6 (CH2
CH2CH). IR (ATR): 3289, 1088, 1051 cm-1. [α]D
23.6 +4.24 ± 1.1 (c = 0.20, CHCl3; sample with ee = 96%).
16 Analytical data for sulfonic acids 7 and 11: 7a: 1H NMR (300 MHz, D2O): δ = 5.83 (d, J = 10.1 Hz, 1 H, CH=CCl2), 3.78-3.88 (m, 1 H, CHS), 1.26 (d, J = 6.9 Hz, 3 H, Me). 13C NMR (75 MHz, D2O): δ = 126.0 (C=C), 123.8 (C=C), 56.6 (CSO3H), 14.8 (Me). IR (ATR): 2941, 1621, 1141, 1007 cm-1. HRMS (ESI): m/z [M - H]- calcd for C4H6O3SCl2: 202.9332; found: 202.9343. [α]D
22.9 -75.46 ± 0.42 (c = 1.30, H2O; sample with ee = 85%). 7b: 1H NMR (300 MHz, D2O): δ = 5.77 (d, J = 10.4 Hz, 1 H, CH=CCl2), 3.57-3.67 (m, 1 H, CHS), 1.79-1.95 (m, 1 H, CHHCHS), 1.41-1.57 (m, 1 H, CHHCHS), 0.79 (t, J = 7.3 Hz, 3 H, Me). 13C NMR (75 MHz, D2O): δ = 125.1 (C=C), 124.9 (C=C), 63.1 (CSO3H), 23.1 (CH2CHS), 10.2 (Me). IR (ATR): 3412, 1663, 1621, 1178, 1039 cm-1. HRMS (ESI): m/z [M - H]- calcd for C5H8O3SCl2: 216.9498; found: 216.9495. [α]D
28.0 -87.32 ± 0.10 (c = 0.95, H2O; sample with ee >99%). 7c: 1H NMR (300 MHz, D2O): δ = 5.77 (d, J = 10.4 Hz, 1 H, CH=CCl2), 3.66-3.77 (m, 1 H, CHS), 1.70-1.85 (m, 1 H, CHHCHS), 1.42-1.59 (m, 1 H, CHHCHS), 1.07-1.36 (m, 2 H, CH
2CH3), 0.75 (t, J = 7.3 Hz, 3 H, Me). 13C NMR (75 MHz, D2O): δ = 125.4 (C=C), 124.7 (C=C), 61.3 (CSO3H), 31.5 (CH2CHS), 19.1 (CH2CH3), 12.8 (Me). IR (ATR): 2958, 1622, 1198, 1080 cm-1. HRMS (ESI): m/z [M - H]- calcd for C6H10O3SCl2: 230.9655; found: 230.9654. [α]D
26.4 -79.53 ± 0.14 (c = 1.20, H2O; sample with ee = 86%). 7d: 1H NMR (300 MHz, D2O): δ = 5.83 (d, J = 10.4 Hz, 1 H, CH=CCl2), 3.99 (td, J = 3.7, 10.4 Hz, 1 H, CHS), 3.64 (td, J = 5.4, 10.9 Hz, 1 H, CHHCl), 3.37-3.38 (m, 1 H, CHHCl), 2.23-2.36 (m, 1 H, CHHCHS), 1.96-2.28 (m, 1 H, CHHCHS). 13C NMR (75 MHz, D2O): δ = 126.0 (C=C), 124.0 (C=C), 59.0 (CSO3H), 41.7 (CH2Cl), 32.5 (CH2CHS). IR (ATR): 2539, 1621, 1193, 1060 cm-1. HRMS (ESI): m/z [M - H]- calcd for C5H7O3SCl3: 250.9109; found: 250.9109. [α]D
28.5 -134.18 ± 0.07 (c = 1.37, MeOH; sample with ee = 94%). 7e: 1H NMR (300 MHz, D2O): δ = 7.20-7.35 (m, 5 H, CHPh), 5.94 (d, J = 10.3 Hz, 1 H, CH=CCl2), 4.09 (m, 1 H, CHS), 3.37 (dd, J = 3.1, 13.7 Hz, 1 H, CHHPh), 2.82 (m, 1 H, CHHPh). 13C NMR (75 MHz, D2O): δ = 139.7 (CPh,q), 131.7 (2 × CPh), 131.1 (2 × CPh), 129.3, 127.9, 127.2 (C=C), 65.5 (CSO3H), 38.5 (CH2Ph). IR (ATR): 3029, 1621, 1216, 1154, 1038 cm-1. HRMS (ESI): m/z [M - H]- calcd for C10H10O3SCl2: 278.9655; found: 278.9654. [α]D
23.8 -75.97 ± 0.13 (c = 0.95, MeOH; sample with ee = 99%). 7f: 1H NMR (300 MHz, D2O): δ = 6.75-6.85 (m, 4 H, CHPh), 5.84 (d, J = 10.6 Hz, 1 H, CH=CCl2), 3.90-4.05 (m, 2 H, CHS, CH2OAr), 3.75-3.87 (m, 1 H, CH2Cring), 3.63 (s, 3 H, OMe), 2.23-2.39 (m, 1 H, CH
2CHS), 1.81-1.97 (m, 1 H, CH
2CHS). 13C NMR (75 MHz, D2O): δ = 153.2 (CPh), 151.9 (CPh), 125.2 (C=C), 124.4 (C=C), 116.4 (2 × CHPh), 114.8 (2 × CHPh), 65.9 (CH2O), 58.9 (CSO3H), 55.7 (OMe), 29.5 (CH2CHS). IR (ATR): 3422, 1621, 1509, 1216, 1167, 1032 cm-1. HRMS (ESI):
m/z [M - H]- calcd for C12H14O5SCl2: 338.9866; found: 338.9866. [α]D
20.3 -80.63 ± 0.26 (c = 0.55, MeOH; sample with ee >99%). 11b: 1H NMR (300 MHz, D2O; E-isomer): δ = 6.34 (d, J = 13.4 Hz, 1 H, CH=CHCl), 5.81 (dd, J = 10.3, 13.4 Hz, 1 H, CH=CHCl), 3.38 (dt, J = 3.7, 10.3 Hz, 1 H, CHS), 1.88-2.04 (m, 1 H, CHHCHS), 1.50-1.66 (m, 1 H, CHHCHS), 0.86 (t, J = 7.5 Hz, 3 H, Me). 1H NMR (300 MHz, D2O; Z-isomer): δ = 6.45 (d, J = 7.2 Hz, 1 H, CH=CHCl), 5.74 (dd, J = 7.2, 10.3 Hz, 1 H, CH=CHCl), 3.95 (dt, J = 3.2, 10.3 Hz, 1 H, CHS), 1.88-2.04 (m, 1 H, CHHCHS), 1.50-1.66 (m, 1 H, CHHCHS), 0.87 (t, J = 7.5 Hz, 3 H, Me). 13C NMR (75 MHz, D2O; E-isomer): δ = 127.9 (C=C), 123.0 (C=C), 64.1 (CSO3H), 22.7 (CH2CHS), 10.6 (Me). 13C NMR (75 MHz, D2O; Z-isomer): δ = 126.3 (C=C), 123.6 (C=C), 60.5 (CSO3H), 23.2 (CH2CHS), 10.4 (Me). IR (ATR): 2973, 1694, 1115 cm-1. HRMS (ESI): m/z [M - H]- calcd for C5H9O3SCl: 182.9888; found: 182.9889.