HOCH2CH2CHCH2

HOCH2CH2CHCH2 is a condensed structural representation of a four-carbon alcohol fragment. In this notation, the hydroxyl group is on the terminal carbon, giving a CH2OH unit at one end, followed by two methylene units and a central secondary carbon (the third carbon in the chain) that bears a hydrogen. The final carbon is a terminal methylene. As presented, this fragment does not by itself constitute a complete, isolable compound because the central carbon (C3) would require an additional substituent or bond to satisfy valence.

In practical terminology, this fragment can be viewed as a butyl-derived hydroxyalkyl skeleton. When attached to a larger molecule, the naming and identity depend on the substituents at the central carbon and the point of connection to the rest of the structure. For example, it could occur as part of a larger alcohol, ether, or ester, where the CH2OH unit becomes a reactive handle for further functionalization.

Chemical properties follow those typical of primary and secondary alcohol fragments: the molecule is polar, can participate in hydrogen bonding, and may undergo oxidation or esterification reactions under appropriate conditions. As a fragment, its reactivity is highly context-dependent, governed by the substituents and the overall molecular framework to which it is attached.

See also: butanol isomers, hydroxyalkyl groups, and common functional-group strategies in organic synthesis.