Lewis acids are chemical compounds that are able to accept a pair of electrons to form a covalent bond. These compounds are commonly used as catalysts in organic synthesis, a process that involves the synthesis of organic compounds from simpler starting materials.

One of the main advantages of Lewis acids is their ability to facilitate a wide range of organic synthesis conversions, including nucleophilic substitution, electrophilic addition, and elimination reactions. These reactions involve the transfer of electrons between reactant molecules, leading to the formation of new chemical bonds and the synthesis of new compounds.

Examples of common Lewis acids used in organic synthesis include aluminum chloride (AlCl3), boron trifluoride (BF3), and iron trichloride (FeCl3). These compounds are able to accept a pair of electrons from a nucleophile, such as a negatively charged molecule or an atom with a lone pair of electrons, and form a covalent bond with it.

In the cannabis industry, Lewis acids are particularly useful for cannabinoid isomerization and conversion, enabling processors to transform CBD into various THC isomers through controlled catalytic reactions.

Frequently Asked Questions

Which Lewis acids are used to convert CBD to THC?

Boron trifluoride, usually as its diethyl etherate, and zinc chloride are the Lewis acids that show up in CBD conversion; p-toluenesulfonic acid does the same cyclization as a Bronsted acid. The full isomerization chemistry and SOP are in our CBD to THC conversion guide.

Why does the acid change how much delta-8 THC you get?

Delta-8 THC is the thermodynamically favored isomer, so a stronger acid, a higher temperature, or a longer reaction pushes delta-9 over into delta-8 and the iso-THC family. Short, cold, quenched reactions keep more delta-9.

Can a lab tell that a THC product was made with a Lewis acid?

Often, yes. Delta-8 above 1 percent, delta-10 or iso-THC at any level, and boron or zinc residues point to acid conversion, and boron and zinc are not on the standard four-metal panel. See How to Detect Converted THC; the acid-side version of the question is in CBDA to THCA Conversion.