mole in 30 ml ch 2 cl 2 was added over one hour after stirring at 5 u00b0 c for 0 5 hour h 2 o 200 ml at 5 u00b0 c was added the layers were separated and the aqueous layer washed 1 u00d7 100 ml ch 2 cl 2 the combined organic layers were washed in sequence 1 u00d7 100 ml h 2 o 1 u00d7 100 ml 1n hcl 1 u00d7 100 ml h 2 o 1 u00d7 100 ml saturated nahco 3 and 1 u00d7 100 ml h 2 o dried over mgso 4 filtered and concentrated in vacuo to yield title product as an oil 72 2 g 98 5 alpha d 25 7 7 c 1 00 chcl 3 r f 0 6 ch 2 cl 2 under nitrogen with stirring sodium iodide 90 g 0 6 mole was dissolved in one liter dry acetone at 32 u00b0 c 2s benzyloxy 1 propyl mesylate 71 5 g 0 293 mole was added the reaction mixture was warmed to 59 u00b0 60 u00b0 c gentle reflux and held for 20 hours at which time tlc indicated about 20 starting material to remain additional sodium iodide 30 g 0 2 mole was added and refluxing continued for 3 hours the reaction was cooled to room temperature and filtered with acetone wash the combined filtrate and wash was concentrated to 150 ml of oily solids diluted with 300 ml toluene and 200 ml h 2 o the layers separated and the aqueous phase extracted 2 u00d7 100 ml toluene the three organic layers were combined washed 2 u00d7 200 ml h 2 o dried over mgso 4 filtered and evaporated to yield title product.