Pseudolimonene

Pseudolimonene is a naturally occurring organic compound found in certain plant species, particularly in the essential oils of various aromatic herbs. It is a monoterpene with the chemical formula C₁₀H₁₆, characterized by a unique structure that includes a cyclohexene ring with a double bond and an isopropenyl (3-methyl-1-propenyl) group. Pseudolimonene gets its name due to its structural similarity to limonene, a well-known terpene found in citrus fruits. The "pseudo" prefix indicates that while the structure resembles limonene, it is not identical. 

Psuedolimonene is the least common of the limonenes that have been observed in cannabis. The quantitative amount of the compound in the plant is so rare  that most testing facilities do not even have analytical standards to test for it. Pseudolimonene is often seen as an impurity in other terpene isolates in trace amounts.