(4R,2'R,3'R,5'R)-3-[5-(tert-Butyldimethylsilyloxy)-1-oxo-2,3-bis(phenylmethoxy)hexyl]-4-(phenylmethyl)-2-oxazolidinone

To a suspension of sodium hydride (5.9 mg, 60% in oil, 0.15 mmol) in tetrahydrofuran (0.34 ml) which contained a few drops of N,N-dimethylformamide, under nitrogen at 0°C, was added alcohol 1 (65 mg, 0.11 mmol) [1] in tetrahydrofuran (1.7 ml). The resultant solution was stirred at 0°C for 1 h. Benzyl bromide (0.016 ml, 0.14 mmol) was added and the reaction mixture warmed to room temperature and stirred for 2 h. The reaction mixture was quenched with sodium dihydrogen phosphate (5 ml, 10 % w/v), extracted with ethyl acetate (3 x 15 ml), washed with water (15 ml) and dried over magnesium sulfate. Removal of the solvent under reduced pressure gave a yellow oil which was purified by flash chromatography using light petroleum-ethyl acetate (9:1) as eluent afforded the title compound 2 (27 mg, 35%) as a colourless oil.

[a]D -39.65 (c 0.315, CHCl3).

1H NMR (400 MHz, CDCl3): 0.04 (6H, s, SiMe2), 0.88 (9H, s, But), 1.13 (3H, d, J6',5' 6.1 Hz, H6'), 2.25-2.36 (2H, m, H4'), 2.87 (2H, d, J1",4 7.3 Hz, CHCH2Ph), 3.36-3.39 (2H, m, H5), 3.80-3.89 (1H, m, H5'), 4.25-4.29 (1H, m, H4), 4.44 (1H, d, Jgem 11.5 Hz, 3'-OCHAPh), 4.49 (1H, d, Jgem 11.5 Hz, 3'-OCHBPh), 4.59 (1H, d, Jgem 11.5 Hz, 2'-OCHAPh), 4.64 (1H, d, Jgem 11.5 Hz, 2'-OCHBPh), 6.31 (1H, t, J 7.6 Hz, H3'), 6.78 (1H, d, J2',3' 8.8 Hz, H2'), 7.12-7.36 (15H, m, Ph).

EI-MS: 617 (M+, 1%), 568 (52), 500 (24), 472 (M-C7H18OSi, 5), 434 (M-CH3Ph-CH3Ph, 9), 325 (M-C17H29O2Si, 51), 159 (C8H19OSi, 54), 91 (CH2Ph, 100), 73 (75).

Anal. calc. for C36H47NO6Si M+ (EI), 617.3173; found M+, 617.3171.