Adding ozone to them and then water produces carboxylic acids, while adding water in the presence of a mercury salt produces an enol which tautomerizes to form a ketone, and adding hydrogen in the presence of Lindlar's catalyst partially reduces them to alkenes.  
The Diels-Alder reaction involving 1,3-butadiene and this class's simplest compound produces 1,4-cyclohexadiene.  Adding ozone to them and then water produces carboxylic acids, while adding water in the presence of a mercury salt produces an enol which tautomerizes to form a ketone, and adding hydrogen in the presence of Lindlar's catalyst partially reduces them to alkenes.  FTP, name this class of compounds with formula CnH2n-2 [C-n-H-2n minus 2] whose simplest member is acetylene and which is characterized by a carbon triple bonded to a carbon.
The Diels-Alder reaction involving 1,3-butadiene and this class's simplest compound produces 1,4-cyclohexadiene.  
alkynes