HYDROXYMETHYLATION OF ALDONOLACTONES AND A CHEMICAL SYNTHESIS OF 3-DEOXY-3-FLUORO-D-FRUCTOSE

(Benzyloxymethyl)lithium, generated in situ from butyllithium and (ben zyloxymethyl)tri-n-butylstannane, was found to be an efficient reagent for the monohydroxymethylation of aldono-1,4-lactones to form ketoses . Thus, 4-hydroxy butanoic-1,4-lactone, 2-deoxy-2-fluoro-3,5-di-O-(met hoxymethyl)-D- arabinono-1,4-lactone, ,3,5-tri-O-(methoxymethyl)-D-ara binono-1,4-lactone oxymethyl)-2,3-O-methylidene-D-ribono-1,4-lactone, 5,6-tetra-O-(methoxymethyl)-D-altrono-1,4-lactone, 2,3:5,6-di-O-isopro pylidene-D-gulono-1,4-lactone and 2,3-O-isopropylidene-L-erythrono-1,4 -lactone were respectively converted to 1-benzyloxy-5-hydroxy-2-pentan one, -fluoro-4,6-di-O-(methoxymethyl)-D-fructofuranose, nzyl-3,4,6-tri -O-(methoxymethyl)-D-fructofuranose, (methoxymethyl)-2,3-O-methylidene -D-psicofuranose, 1-O-benzyl-3,4,6,7-tetra-O-(methoxymethyl)-D- altro- heptulofuranose, 1-O-benzyl-3,4:6, 7-di-O-isopropylidene-D-gulo-heptul ofuranose, and zyl-3,4-O-isopropylidene-L-erythro-pentulofuranose in 6 3-81% yields. By deprotection of eoxy-3-fluoro-4,6-di-O-(methoxymethyl )-D-fructose, 3-deoxy-3-fluoro-D-fructose was prepared for the first t ime.