A method for the manufacture of cannabidiol (2-[(1R,6R)-3-methyl-6-prop-1-en-2-yl-1-cyclohex-2-enyl]-5-pentylbenzo-1,3-diol)or pentyl-substituted derivatives thereof, characterized by - silylation of substituted or unsubstituted olivetol (5-pentylresorcinol) in the pentyl residue with TBSCl ( tert -butyldimethylsilyl chloride, according to the following reaction diagram wherein the pentyl substituents are substituted with substituents chosen from the group made up of: hydrogen, deuterium or tritium, alkoxy, such as methoxy (-OCH 3), ethoxy (-OC 2 H 5), nitro (-NO 2), fluorine (-F), chlorine (-Cl), bromine (-Br), alkyl of methyl, ethyl, propyl to butyl, as a result of which a correspondingly unsubstituted (R = H) or Di-O- tert -butyldimethylsilyl-5-pentylresorcinol is obtained - bromination of the Di-O- tert -butyldimethylsilyl-5-pentylresorcinol obtained in the first step and possibly substituted to Di-OTBS-dibromolivetol (4,6-dibromo-di-O- tert -butyldimethylsilyl-5-pentylersorcinol), - desilylation of the Di-OTBS-dibromolivetol (4,6-dibromo-di-O- tert- butyldimethylsilyl-5-pentylresorcinol) obtained in the preceding step and possibly substituted to dibromolivetol (4,6-dibromo-5-pentylresorcinol) or the correspondingly substituted derivative, - conversion of the dibromolivetol obtained in the preceding step (4,6-dibromo-5-pentylresorcinol) or the correspondingly substituted derivative with trans- menthadienol (4R-isopropenyl-1-methylcyclohex-2-enol) into dibromo-cannabidiol or its correspondingly substituted derivative, - debromation of the dibromo-cannabidiol obtained in the preceding step or its correspondingly substituted derivative into cannabidiol or its corresponding derivative. - silylation of substituted or unsubstituted olivetol (5-pentylresorcinol) in the pentyl residue with TBSCl ( tert -butyldimethylsilyl chloride, according to the following reaction diagram wherein the pentyl substituents are substituted with substituents chosen from the group made up of: hydrogen, deuterium or tritium, alkoxy, such as methoxy (-OCH 3), ethoxy (-OC 2 H 5), nitro (-NO 2), fluorine (-F), chlorine (-Cl), bromine (-Br), alkyl of methyl, ethyl, propyl to butyl, as a result of which a correspondingly unsubstituted (R = H) or Di-O- tert -butyldimethylsilyl-5-pentylresorcinol is obtained hydrogen, deuterium or tritium, alkoxy, such as methoxy (-OCH 3), ethoxy (-OC 2 H 5), nitro (-NO 2), fluorine (-F), chlorine (-Cl), bromine (-Br), alkyl of methyl, ethyl, propyl to butyl, as a result of which a correspondingly unsubstituted (R = H) or Di-O- tert -butyldimethylsilyl-5-pentylresorcinol is obtained - bromination of the Di-O- tert -butyldimethylsilyl-5-pentylresorcinol obtained in the first step and possibly substituted to Di-OTBS-dibromolivetol (4,6-dibromo-di-O- tert -butyldimethylsilyl-5-pentylersorcinol), - desilylation of the Di-OTBS-dibromolivetol (4,6-dibromo-di-O- tert- butyldimethylsilyl-5-pentylresorcinol) obtained in the preceding step and possibly substituted to dibromolivetol (4,6-dibromo-5-pentylresorcinol) or the correspondingly substituted derivative, - conversion of the dibromolivetol obtained in the preceding step (4,6-dibromo-5-pentylresorcinol) or the correspondingly substituted derivative with trans- menthadienol (4R-isopropenyl-1-methylcyclohex-2-enol) into dibromo-cannabidiol or its correspondingly substituted derivative, - debromation of the dibromo-cannabidiol obtained in the preceding step or its correspondingly substituted derivative into cannabidiol or its corresponding derivative.