What is but-2-en-1-al?

Answer 1

Yes it is true . According to latest IUPAC rules of 1993 2-butenal is more precisely written as but-2-en-1-alIt is dehydrated product of aldol. Common name is crotonaldehyde but-2-en-1-al & but-2-enal both are 100 % correct because their meaning is same & is a unique name Ref : latest Rules of IUPAC published in 1993

Answer 2

It is the most correct IUPAC name of crotonaldehyde. It is dehydrated product of aldol i.e. 3 hydroxy butanal & it is internationally accepted According to latest IUPAC nomenclature i.e. 1993 IUPAC nomenclature but-2-en-1-al is most correct i.e. 100 % correct than 2-butenal ( 1979 IUPAC nomenclature system which is not in use today.) -From the journal of latest IUPAC discussions & publishings.

Answer 3

CH3-CH=CH-CHO

Is but-2-en-1-al

NB THE CHO is the aldehyde functional group R-C- H(=O)