AIDS-006842 AIDS006842 TSAO 1,2,3-triazole deriv. [1-[2',5'-Bis-O-(tert-butyldimethylsilyl)-.beta-D-ribofuranosyl]-4,5-bis[(ethoxy)carbonyl]-1,2,3-triazole]-3'-spiro-5''-(4''-amino-1'',2''-oxathiole 2'',2''-dioxide)