Reaction Steps
Diethyl L-tartrate [(2R,3R)-diethyl 2,3-dihydroxysuccinate] was converted to (2S,3R)-diethyl 2-azido-3-hydroxysuccinate according to the literature method (A. Breuning, R. Vicik and T. Schirmeister, Tetrahedron: Asymm., 2003, 14, 3301) and then into (S)-ethyl 2-azido-2-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)acetate according to the method described by S. Saito, T. Ishikawa, A. Kuroda, K. Koga and T. Moriwake, Tetrahedron, 1992, 48, 4067. This latter compound (1.8 g, 7.85 mmol) was dissolved in dry THF (12 ml) and cooled in an ice-bath. Lithium aluminium hydride (31.4 ml, 31.4 mmol, 1M in diethyl ether) was added and the mixture warmed to rt and stirred for 30 mins., then heated under reflux for 3 h. The mixture was cooled in an ice bath and water (1.2 ml), 15% aq. NaOH (1.2 ml), and water (4 ml) added successively. The mixture was diluted with diethyl ether, filtered through Celite and the Celite washed with hot CHCl3 (3×). The combined filtrates were dried (MgSO4), filtered and the solvent evaporated to a colourless oil. The oil was chromatographed on silica gel (CH2Cl2-MeOH-28% aq. NH4OH, 96:4:0.5 then 9:1:0.05) to give a pale yellow oil which was distilled on a Kugelrohr apparatus at 120° C./0.1 mmHg to afford (R)-2-amino-2-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)ethanol (0.415 g, 61%) as a colourless oil. 1H NMR (CDCl3, referenced to the centre line of CDCl3 at 77.0 ppm) δ 4.10-3.98 (m, 2H), 3.87 (dd, J=7.4, 5.7 Hz, 1H), 3.71 (dd, J=10.9, 4.4 Hz, 1H), 3.54 (dd, J=10.9, 5.7 Hz, 1H), 2.95 (m, 1H), 1.94 (brs, 3H, exchanged to D2O), 1.42 (s, 3H), 1.35 (s, 3H). 13C NMR (CDCl3) δ 109.0, 77.8, 66.5, 64.4, 54.6, 26.5, 25.2. +ESMS Found 162.1130 (M+H)+ C7H16NO3 requires 162.1130. [α]D20 −9.5 (c, 1.47, CHCl3). Lit., [α]D −10.5, c 1.5, CHCl3 for the product made from D-ascorbic acid according to M. Banwell, C. De Savi, D. Hockless and K. Watson, Chem. Commun., 1998, 645.
