2,2,4,4-Tetramethyl-1,3-cyclobutanediol
2,2,4,4-Tetramethyl-1,3-cyclobutanediol (CBDO) is an aliphatic diol. This diol is produced as a mixture of cis- and trans-isomers, depending on the relative stereochemistry of the hydroxyl groups.
Source: Wikipedia — 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (CC BY-SA 4.0)