PhNH2 was o-substituted with styrene oxide or cyclohex-enoxide to PhCH(NHPh)CH2OH (2) or o-PhNHC6H10OH (trans-4), resp., condensed then with citronellal (5) or hydrocynamic aldehyde (6) at b.p. in presence of p-tosyl acid to resp. 1,3-oxazolidines (7) or (8). The alc. 4 showed a trans-configuration. Its isomerization to cis-4 was carried out by diacetylation, selective hydrolysis of the AcO group with K2CO3 in MeOH/H2O, transfer of Ac group from NH to OH and simultaneous change of the OH group configuration from trans to cis in presence of mesyl chloride and Et3N and final hydrolysis of AcO group with K2CO3 in MeOH (yield about 20%). The cis-4 was also condensed with 5 or 6 to resp. 12 or 13. All intermediates and products were studied for repelling and acaricidic activities against housefly (Musca domestica) and 2-spotted spider mite (Tetranychus urticae). The alcs. 2, trans-4 and cis-4 showed low repellent efficiency (below 40%) while the oxazolidines 7 and 8 were more efficient 96.8% and 61.3%, resp. The aldehydes 5 and 6 used for the synthesis showed also repellent activity 97.5% and 54.8%, resp. The repellent activity of geraniol used for comparison was 100%. The 12 and 13 isomers were found even attractant of the housefly (repellent activity - 2.5%, and - 34.8%, resp.). Neither the intermediates nor products did show any remarkable acaricidic activity, but showed some repellent activity (trans-4 55%, 2 35%, 12 32.5% and 13 30%) lower however than that of m-MeC6H4NEt2 used for comparison (60%).