In
organic chemistry, an
alkyl substituent is an
alkane missing one
hydrogen. The term alkyl is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula C
nH
2n+1. A
cycloalkyl is derived from a
cycloalkane by removal of a hydrogen atom from a ring and has the general formula C
nH
2n-1. Typically an alkyl is a part of a larger molecule. In
structural formula, the symbol R is used to designate a generic (unspecified) alkyl group. The smallest alkyl group is
methyl, with the formula CH
3-.