1.Twelve previously undescribed alkylgeranylacetic acids containing alkyl substituents with from 1 to 15 carbon atoms and thirteen corresponding alkylgeranylmalonic esters were synthesized and characterized. Three previously undescribed 2-alkyl-5,9-dimethyldecanoic acids were also prepared and characterized.2.The previously undescribed dibutyl geranylmalonate and dibutyl ethylgeranylmalonate were synthesized and characterized.3.Some data are given on the relation of the biological properties of disubstituted acetic acids to their structures: the bacteriostatic action of alkylgeranylacetic acids becomes more intense as the degree of branching of the alkyl substituent increases. The bacteriostatic action of alkyldimethyldecanoic acids is only slightly weaker than that of the corresponding unsaturated acids.