The present invention is directed to compounds of formula (I): wherein R1 represents C4-C7 branched alkyl group, a bicycloalkyl group, or a C5-C6 cycloalkyl which optionally may be substituted with a C1-C4 alkyl group; R2 represents hydrogen, a methyl group, which may be in either the α or β configuration, or a methylene group; R3 and R4 are the same or a different group and each independently represents hydrogen, halogen or a methyl group; represents a single or a double bond; and physiologically acceptable solvates thereof, physiologically functional derivatives thereof, pharmaceutical compositions comprising the compounds, the use of the compounds for the manufacture of medicaments particularly for the treatment of inflammatory and/or allergic conditions, processes for the preparation of the compounds, and chemical intermediates in the processes for the manufacture of the compounds.