141684-49-3 5'-Silyl-2'dT TSAO deriv. AIDS-004712 AIDS004712 [1-[5'-O-(tert-Butyldimethylsilyl)-2'-deoxy-.beta.-D-erythropentofuranosyl]thymine]-3'-spiro-5-[4-amino-1,2-oxathiole-2,2-dioxide]