Abstract: Antivirally active compounds of formula (I), wherein R.sup.1 is hydrogen, hydroxy, mercapto or amino; R.sup.2 is hydrogen, hydroxy, fluoro, chloro or amino; R.sup.3 and R.sup.4 are independently selected from (II), (III), amino, hydroxy or an ether or ester residue thereof, or R.sup.3 together with R.sup.4 is (IV), wherein M is hydrogen or a pharmaceutically acceptable counterion; and n is 1 or 2; with the proviso that, when R.sup.2 is amino and R.sup.3 and R.sup.4 are hydroxy R.sup.1 is not hydroxy and in addition, when n=1, R.sup.1 is not hydrogen, and pharmaceutically acceptable salts thereof; processes for preparation of said compounds, a pharmaceutical composition comprising said compounds, methods for treatments of virus infections as well as use of compounds of formula (I) without the proviso for the manufacture of a medicament for treatment of AIDS.

Abstract: Use of a compound of the formula ##STR1## wherein A is .beta.-2'-deoxy-D-ribofuranosyl or .beta.-D-arabinofuranosyl;R.sup.1 is hydroxy or amino;R.sup.2 is cycloalkyl or alkyl-substituted cycloalkyl containing 1-5 carbon atoms; saturated or unsaturated, straight or branched alkyl containing 1-5 carbon atoms which may be unsubstituted or substituted with halogen, hydroxy, mercapto, trifluoroalkyl or difluoroalkyl containing 1-3 carbon atoms, phenoxy or alkoxy containing 1-3 carbon atoms; phenyl or phenylalkyl containing 1-3 carbon atoms in the alkyl part, or a physiologically acceptable salt thereof,for manufacture of a medicament for therapeutic or prophylactic control or treatment of retrovirus, especially HIV, or hepatitis B virus infections in animal and man and to a method of such treatment.

Abstract: A compound of the formula ##STR1## wherein the radicals A, X, R.sup.1, R.sup.2 and R.sup.3 are defined as follows: ##STR2## R.sup.2 : H; or R.sup.2 constitutes together with R.sup.3 with a carbon - carbon bondR.sup.3 : H; F; Cl; Br; I; N.sub.3 ; CN; C.tbd.CH; OH; OCH.sub.3 ; CH.sub.2 OH; and when R.sup.3 is F; Cl; Br; I; N.sub.3 ; CN; C.tbd.CH; OH; OCH.sub.3 or CH.sub.2 OH it may have either the cis-configuration or trans-configuration relative to the hydroxymethyl function at position 4', or R.sup.3 constitutes together with R.sup.2 a carbon - carbon bond, and therapeutically acceptable salts thereof, for use in therapy, in particular for the treatment of HIV infections.

Abstract: Antivirally active compounds of the formula ##STR1## wherein R.sub.1 is hydrogen or hydroxymethyl;R.sub.2 is hydrogen, hydroxy or hydroxymethyl;R.sub.3 is hydrogen; or R.sub.1 and R.sub.3 together constitute an additional carbon-carbon bond;with the proviso that when R.sub.1 is hydrogen then R.sub.2 is hydroxy or hydroxymethyl, that when R.sub.1 is hydroxymethyl then R.sub.2 is hydrogen and that when R.sub.2 is hydroxy then R.sub.1 is hydrogen; and physiologically acceptable salts; geometric or optical isomers thereof; processes for preparation of said compounds, pharmaceutical preparations containing the compounds, methods for treatment of virus infections and medical use of the compounds.

Abstract: Antivirally active compounds of the formula ##STR1## wherein A is ##STR2## wherein m is 1 or 2,n is 1 or 2, whereby m is 1 when n is 2 and m is 2 when n is 1,R.sub.a ' is (CH.sub.2).sub.p OH, NHCONH.sub.2 or COR.sub.a ",R.sub.a " is hydrogen, hydroxy or amino,p is 1 to 4,R.sub.b ' and R.sub.b " are independently selected from hydrogen or (CH.sub.2).sub.p OH,with the proviso that at least one of R.sub.b ' or R.sub.b " is hydrogen; orR.sub.b ' and R.sub.b " together constitute an additional carbon-carbon bond to form an alkyne; or a physiologically acceptable salt, geometric or optical isomer thereof; pharmaceutical preparations containing the compounds and methods for treatment of virus infections.