Synthesis of (-)-trans-delta-9-tetrahydrocannabivarin (delta-9 thcv) and analogs thereof

A method for synthesizing a Δ9 cannabinoid having the structure of formula (II)

• wherein:
• R1 is selected from C1-C12 hydrocarbyl, substituted C1-C12 hydrocarbyl, heteroatom-containing C1-C12 hydrocarbyl, and substituted heteroatom-containing C1-C12 hydrocarbyl,
• R2, R3, and R5 are independently selected from C1-C6 alkyl and substituted C1-C6 alkyl;
• m is zero, 1 or 2;
• and
• R4 is OH or OR6 wherein R6 is H, C1-C6 alkyl, Cs-C12 aryl, or a hydroxyl protecting group, with the proviso that when m is 2, the R4 may be the same or different,
• wherein the method comprises:
• (a) combining a cannabinoid reactant having the structure of formula (I)
• with an acid in a solvent for the cannabinoid reactant and the acid to provide a reaction mixture, wherein the acid comprises (i) a Lewis acid having an acid softness index value in the range of −10 ΔG0f, Mn+ to −150 ΔG0f, Mn+, (ii) a Brønsted acid having a pka in the range of −4.0 to +4.0, or (iii) a combination of (i) and (ii), under reaction conditions comprising a reaction temperature in the range of-0°° C. to 25°° C. and a reaction time in the range of 1 hour to 24hours;
• (b) quenching the reaction mixture of (a) with a base;
• and
• (c) removing the solvent to provide a reaction product comprising the Δ9 cannabinoid having the structure of formula (II).