HOMOCYKLISKE APHIDICOLANDERIVATER OG FREMGANGSMAADE TIL FREMSTILLING DERAF

Aphidicolane derivatives of the formula: wherein R1 stands for hydrogen or a hydroxy radical, R2 stands for a hydroxy or methyl radical, or the group CR1R2 stands for a keto group; R3 stands for a formyl or hydroxymethyl radical, or for the group -CH2O.CO.OR6, wherein R6 stands for a defined radical or R2 and R3 are joined together to form the group -O.CO.OCH2-; R4 stands for a hydroxy radical; R5 stands for a formyl radical, a hydroxyalkyl radical -(CH2)1-3OH, a radical -CHR7OH, wherein R7 stands for a defined radical, or R5 stands for an azidomethyl or pyrrolidinylcarbonyloxymethyl radical, or for the group -CH2O.CO.OR8, wherein R8 stands for a defined radical, or R5 stands for the group -CH2O.CO.(CH2)m.CR11R12.(CH2)n.NR9R10, wherein m, n, R9, R10, R11 and R12 have defined values, or R5 stands for the group -CH2O.SO2.R13, wherein R13 stands for a defined radical; or R4 and R5 are joined together to form the group -O.CH2- or -O.CO.OCH2-; and, where appropriate, pharmaceutically-acceptable salts thereof. Processes for the preparation of said aphidicolane derivatives. Pharmaceutical compositions comprising one of the compounds and a pharmaceutical diluent or carrier. The compounds exhibit inhibitory activity against DNA-containing viruses and they inhibit the growth of some tumors.