Benzyl Bromide → Methyl 2-benzyl-3-hydroxypropanoate

β-Propiolactone (A) is dissolved in methanol and treated with 1 equivalent of triethylamine to produce methyl 3-hydroxypropionate (B). Compound B is converted to the dianion with 2 equivalents of lithium diisopropylamide and alkylated with 1 equivalent of benzyl bromide to produce methyl 2-benzyl-3-hydroxypropionate (C). Compound C is protected as the t-butyldimethylsilyl ether (D). Compound D is then saponified with potassium hydroxide and carefully acidified to produce the acid (E). The acid (E) is then dissolved in tetrahydrofuran, treated with 1 equivalent of N-methylmorpholine and cooled to -20° C. One equivalent of isobutyl chloroformate is added, followed by 1 equivalent of 5,6-diamino-1,3-dipropyluracil in dimethyl-formamide to produce the amide. The amide is then treated with aqueous potassium hydroxide at 70° C. to produce the cyclized, deprotected 3,7-dihydro-8[(R)-1-methyl-2-phenyl-ethyl]1, 3-dipropyl-1H-purine-2,6-dione. ##STR8##