Ahstractz The acctyknii alcohol, 3, readily prepared in two steps from propargyl bromide. 1. is converted to ethyl 2dcoxy-D-xy1ofuTan0side. l3, and to the unnamml L-cnantiomer. 12, in 5 steps and 50% overall yield, utilizing asymmetrk dihydroxylation (AD) of alkcne 7 for intro&&m df chMity. A similar strategy from the. isomcric Zallylic alcohol, 4, afhudai the 2&oxy-L-ribofuranosidc, but in modest alantiomeric excess. The stereoselective synthesis of carbohydrates from acyclic non-carbohydrate precursors continues to be an -focus for anmnba ofnxzarch gcoups.t~* Asymmetric synthesis of carbohydrates ftomreadily availableuctiml in~isanranctivegoplo~sevcnldv~~over,andcomplimauaryto,chiron~~. Inpartict& if~rrsynnneaicmdhodoloeycanbeernployedforwhichbathenantiomericv~areRadilyav~,~bothnafural . . and~CUbohYdlXtCstatochemurtnes ~bCObt&Cdfroma-subiitrate.~3 A de rulyo approach could also of&k the pobmtial of introducing isotopic labels or other subsdtucnt pattcms (dcoxy. alkyl substituted) which would be pmbkznatktointroduceviaachinmappmach We have previously qofted the conversion of a simple five E-allyJic alcoholto a number of ikanoaidcs of borhD-andLulant.i~ series, arxI to derived nxxli&d nuclcosideq for example AZ&h ddC=' and d4T,k utilkiq the s~Katsukiasymmmiccpkd&alfori#mduuioItofchMity. We an+isaged that asymumic dihydmxylatim (ADP off&s a potmtkUy complimmtary approa& to the synthesis of the Ft 2-dcoxycarbohydrates from the m E-allylic alcohol and/or from the isomuic zallylic alcohol. we report here an improved route to the E-dlylic alcohol, 5. and its conversion in only 4 steps, in high yield and good ala&J&&vity, to both the 2-dwxy-L-and BxyloM alanti-, Milking asymaIe&k dihydIVxylatial+ -Bf 50% 80-90% 1 2 3 6755