7-SpiroOxathioldiTBSRiboHx 7-TSAO-H 7-[2',5'-Bis(t-butyldimethylsilyl)-3'-spiro-5-(4-amino-1,2-oxathiole-2,2-dioxide)ribofuranosyl]hypoxanthine AIDS-003939 AIDS003939 TSAO-7Hx [7-[2',5'-Bis-O-(tert-butyldimethylsilyl)-.beta.-D-ribofuranosyl]hypoxanthine]-3'-spiro-5-(4-amino-1,2-oxathiole-2,2-dioxide)