L-Alanine, N-[(R)-hydroxyphenoxyphosphinyl]-, 1-methylethyl ester, 5′-ester with 9-[(2R)-2-deoxy-2-fluoro-4-C-fluoro-2-methyl-β-D-erythro-pentofuranosyl]-6-(1-pyrrolidinyl)-9H-purin-2-amine

L-Alanine, N-[(S)-hydroxyphenoxyphosphinyl]-, 1-methylethyl ester, 5′-ester with 9-[(2R)-2-deoxy-2-fluoro-4-C-fluoro-2-methyl-β-D-erythro-pentofuranosyl]-6-(1-pyrrolidinyl)-9H-purin-2-amine