the solvent was removed under reduced pressure and column chromatography ch 2 cl 2 meoh 4 5 1 of the crude product gave an amorphous solid 219 mg 72 1 h nmr cd 3 od u03b47 53 7 30 5h m ar 5 61 1h s h 5 4 53 1h dd j 11 1 5 2 hz h 4a 4 25 1h m h 2 4 20 1h ddd j 9 8 5 2 4 4 hz h 3 4 11 1h br s h 2 u2032 3 99 3 84 4h m h 1a h 3 u2032 h 5 u2032 a h 5 u2032 b 3 82 1h dd j 10 7 9 8 hz h 4b 3 58 1h m h 1 u2032 a 3 55 3 42 2h m h 1 u2032 b h 4 u2032 3 38 1h m h 1b 13 c nmr 100 6 mhz cd 3 od u03b4138 72 c ipso 130 12 c para 129 21 127 39 4c ortho meta 102 33 c 5 78 01 c 4 u2032 c 3 u2032 c 2 76 31 c 2 u2032 70 29 c 4 69 02 c 3 62 64 c 1 u2032 60 51 c 5 u2032 58 46 c 1 maldi tof ms m e 428 m na 406 m h hrms calcd for c 16 h 23 o 9 sn m h 406 1179 found 406 1192 a mixture of 1 4 dideoxy 1 4 imino l arabinitol 16 80 mg 0 6 mmol and 2 4 o benzylidene.