Search results
Results from the WOW.Com Content Network
A homologous series is a group of compounds that differ by a constant unit, generally a methylene (−CH 2 −) group. The reactants undergo a homologation when the number of a repeated structural unit in the molecules is increased. The most common homologation reactions increase the number of methylene (−CH 2 −) units in saturated chain ...
The name "homologous series" is also often used for any collection of compounds that have similar structures or include the same functional group, such as the general alkanes (straight and branched), the alkenes (olefins), the carbohydrates, etc. However, if the members cannot be arranged in a linear order by a single parameter, the collection ...
Ketones containing alkene and alkyne units are often called unsaturated ketones. A widely used member of this class of compounds is methyl vinyl ketone, CH 3 C(O)CH=CH 2, a α,β-unsaturated carbonyl compound.
More complex alkenes may be named with the E–Z notation for molecules with three or four different substituents (side groups). For example, of the isomers of butene , the two methyl groups of ( Z )-but-2 -ene (a.k.a. cis -2-butene) appear on the same side of the double bond, and in ( E )-but-2-ene (a.k.a. trans -2-butene) the methyl groups ...
Maltose is the two-unit member of the amylose homologous series, the key structural motif of starch. When beta-amylase breaks down starch, it removes two glucose units at a time, producing maltose. An example of this reaction is found in germinating seeds, which is why it was named after malt. [4] Unlike sucrose, it is a reducing sugar. [5]
A chemical formula used for a series of compounds that differ from each other by a constant unit is called a general formula. It generates a homologous series of chemical formulae. For example, alcohols may be represented by the formula C n H 2n + 1 OH (n ≥ 1), giving the homologs methanol, ethanol, propanol for 1 ≤ n ≤ 3.
Alkyl groups form homologous series. The simplest series have the general formula −C n H 2n+1. Alkyls include methyl, (−CH 3), ethyl (−C 2 H 5), propyl (−C 3 H 7), butyl (−C 4 H 9), pentyl (−C 5 H 11), and so on. Alkyl groups that contain one ring have the formula −C n H 2n−1, e.g. cyclopropyl and cyclohexyl.
Otherwise, if the carbonyl position is 2 or 3, the sugar is a derivative of a ketone, and is called a ketohexose, a special case of ketose; specifically, an n-ketohexose. [ 1 ] [ 2 ] However, the 3-ketohexoses have not been observed in nature, and are difficult to synthesize; [ 5 ] so the term "ketohexose" usually means 2-ketohexose.