Lithium, beryllium and boron are elements with atomic numbers 3, 4, and 5, respe

helium fusion involves 6 protons... lithium, beryllium, and boron have less than 6... Be, B, and Li made in beginning of the universe in extremely small quantities<

The process in which helium fuses into carbon was the first thing that came up in my google search. But, this is one area that completely greek to me, and I tried to read around and there doesn't seem to be an answer for this question. Majority of the theories I read just agree on this:

Big Bang Conditions - Evolution
Interaction of the Standard Galactic Cosmic Rays with interstellar medium, supernova spallation and a low energy component related to supernova explosions in galactic superbubbles are all necessary... (origin and production).

It's still greek to me and I don't know of it's relevance to Helium and Carbon.

It's a mystery I guess, there are hundreds of theories but none of them are the answer to your question. This is very interesting! Well good luck!