once with brine the ch 2 cl 2 is removed under reduced pressure at 30 u00b0 c to yield the crude furanosyl bromide as a dark syrup 360 mhz nmr cd 2 cl 2 u03b1 isomer 6 98 d 1h 5 45 dd 1h 4 94 dd 1h 4 64 4 9 m 2h 7 3 8 2 m 15h u03b2 isomer 6 57 s 1h 6 08 d 1h 6 24 dd 1h 5 02 m 1h 4 65 4 9 m 2h 7 3 8 2 m 15h the crude furanosyl bromide is dissolved in 1200 ml of acetone and 60 ml h 2 o after 11 2 hrs the reaction solution is poured into a separatory funnel with 1 l ch 2 cl 2 and washed once with cold h 2 o twice with saturated nahco 3 and once with brine the organic solution is concentrated to about 750 ml and diluted slowly with portions of hexane 1500 ml until crystals began to form crystallization is complete after 18 hrs at 20 u00b0 c and the solids are removed by filtration a second crop may be obtained from the filtrate by evaporating to a syrup redissolving in 250 ml ch 2 cl 2 and diluting to the cloud point with hexane 1400.