The MCAT tends to slant the organic towards the needs of future doctors and away from the needs of future chemical engineers (an influence, not a rule!). The epoxide form might be a minor MCAT favorite because of the importance of epoxides in lipid biosynthesis.

The biosynthesis of steroids involves epoxide formation in the terpene squalene to form squalene 2,3-epoxide. Multiple ring formation in squalene 2,3 epoxide is triggered by epoxide ring opening.