, CH 2 ?CH?CH 2 ), 129.1 (C Ar ), 128.5 (C Ar ), 75 MHz, CDCl 3 ) ? (ppm) 138.6 (Cq Ar ), vol.137
, , vol.697, pp.463-464, 1084.
, HRMS (ESI) m/z calcd for C 24 H 32 NO 6 [M +
, After 20 min at ?78°C, the mixture was quenched with methanol. Dichloromethane (5 mL) and Rochelle salts (1 M, 5 mL) were added. After 18 h of stirring at room temperature, the organic layer was separated and the aqueous layer was extracted with dichloromethane (3 × 10 mL). The combined organic phases were dried (MgSO 4 ), filtered, and concentrated under reduced pressure. After purification by silica gel chromatography (dichloromethane/ acetonitrile, vol.97, p.300
, CDCl 3 ) ? (ppm) 7.52?7.28
, 41 (s, 3H, OMe), 2.90 (d, J = 2.7 Hz, 1H, OH), 2.56?2.54 (m, 2H, CH 2 ?CH?CH 2 ), 101.0 (C1), 79.4 (C4), vol.10
, , vol.3070, pp.696-697, 0918.
, HRMS (ESI) m/z calcd for C 24 H 32 NO 6 [M +
, After 1 h, methanol (0.1 mL), dichloromethane (5 mL), and NaHCO 3 (5 mL) were added, and the phases were separated. The aqueous phase was extracted with dichloromethane (3 × 10 mL), and the combined organic layers were dried (MgSO 4 ), filtered, and concentrated under reduced pressure. Purification by silica gel chromatography (chloroform/ methanol 99.5:0.5) gave 17 (20 mg, 38% over two steps) and 18 (17 mg, 33% over two steps) as colorless films, Preparation of Quaternary Methyl-?-D GlcNAc and ManNAc Derivatives 17 and 18. A solution of 11 (48 mg, vol.3, p.15
, 20 (s, 3H, OMe), 2.45 (dd, J = 14.1, 7.3 Hz, 1H, CH 2 ?CH?CH 2 ), 2.25 (dd, J = 14.1, 7.3 Hz, 1H, CH 2 ?CH?CH 2 ), 1.86 (s, 3H, CH 3 ?C? O), C NMR (75 MHz, CDCl 3 ) ? (ppm) 169.4 (C?O), vol.3
, , vol.3065, pp.478-479, 1087.
, HRMS (ESI) m/z calcd for C 24 H 32 NO 6
, dioxin-7-yl)acetamide (18): R f = 0.28 (silica, chloroform/methanol 99.5:0.5); 1 H NMR (300 MHz, CDCl 3 ) ? (ppm) 7.44?7.15 (m, 10H, H Ar )
, 15 (s, 3H, OMe), 2.46 (dd, J = 15.1, 7.6 Hz, 1H, CH 2 ?CH? CH 2 ), 2.30 (dd, J = 15.1, 6.6 Hz, 1H, CH 2 ?CH?CH 2 ), 1.98 (s, 3H, CH 3 ?C?O); 13 C NMR (75 MHz, CDCl 3 ) ? (ppm) 169.7 (C?O), C Ar ), vol.3, issue.3
, , vol.3358, pp.498-499, 1016.
, HRMS (ESI) m/z calcd for C 24 H 32 NO 6
, Preparation of Quaternary Methyl-?-D GlcNAc and ManNAc Derivatives 19 and 20. A solution of 12 (65 mg, 0.158 mmol) and ammonium acetate (488 mg, 6.331 mmol
, After 1 h, methanol (0.2 mL), dichloromethane (5 mL), and NaHCO 3 (5 mL) were added, and the phases were separated. The aqueous phase was extracted with dichloromethane (3 × 10 mL), and the combined organic layers were dried (MgSO 4 ), filtered, and concentrated under reduced pressure. Purification by silica gel chromatography (dichloromethane/methanol 96:4 to 93:7) gave 19 (23 mg, 32% over two steps) and 20 (21 mg, 29% over two steps) as colorless films. N-((2R,4aR,6R,7R,8R,8aS)-6-Allyl-8-(benzyloxy)-6-methoxy-2-phenylhexahydropyrano[3,2-d][1,3]dioxin-7-yl)acetamide (19): R f = 0.33 (silica, dichloromethane/methanol 95:5); 1 H NMR (300 MHz, mL/1.4 mL) was heated at 80°C under microwave irradiation. After 10 min, NaBH 3 CN (98 mg, 1.58 mmol) was added and the solution was heated at 80°C under microwave irradiation for 5 min
, CH 2 ?CH?CH 2 ), 129.1 (C Ar ), 75 MHz, CDCl 3 ) ? (ppm) 169.6 (C?O), vol.138
, , vol.696, pp.497-498, 1016.
, HRMS (ESI) m/z calcd for C 24 H 32 NO 6
, 54 (s, 1H, H7), 5.10?5.03 (m, 2H, CH 2 ?CH?CH 2 ), 4.75 (d, J = 12.0 Hz, 1H, O?CH 2 ?Ph, silica, dichloromethane/methanol 95:5); 1 H NMR (300 MHz, CDCl 3 ) ? (ppm) 7.45?7.28 (m, 10H, H Ar ), 5.98 (d, J = 9.9 Hz, 1H, NH), 5.75 (ddt, J = 17.2, 10.2, 7.5 Hz, 1H, CH 2 ?CH?CH 2 ), vol.5
, cm ?1 ; HRMS (ESI) m/z calcd for C 24 H 32 NO 6, vol.695, p.458, 1018.
, 17 (silica, cyclohexane/ethyl acetate 5:1); 1 H NMR (300 MHz, vol.5
, 3.67 (dd, J = 11.4, 6.0 Hz, 1H, H4), 3.04 (d, J = 11.4 Hz, 1H, OH), 2.73?2.59 (m, 2H, CH 2 ?CH?CH 2 ), 2.36 (br d, 9.9 Hz, 1H, OH); 13 C NMR (75 MHz, CDCl 3 ) ? (ppm) 137.3 (Cq Ar ), C Ar ), vol.131, issue.9
, 2R,4aR,6R)-6-Allyl-8-hydroxy-6-methoxy-2-phenyl-4, vol.3073, p.3427, 1063.
, (m, 2H, CH 2 ? CH?CH 2 ); 13 C NMR (75 MHz, ?7.29 (m, 5H, H Ar ), 5.97?5.83 (m, 2H, H7, CH 2 ?CH?CH 2 ), 5.63 (br s, 1H, OH), 5.22?5.16 (m, 2H, CH 2 ?CH?CH 2 ), vol.130
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