Any sp2 atom connected to 4 different groups is a chiral centre. mirror Such a carbon is called a chiral carbon atom(asymmetric carbon atom or stereocenter),and is usually denoted with an asterix (*) Ch05 Stereochemistry (landscape) Page 6Ch05 Stereochemistry (landscape) Page 6 Any sp3 atom connected to 4 different groups is a chiral centre. Such a carbon is called a chiral carbon atom (asymmetric carbon atom or stereocenter), and is usually denoted with an asterix (*). A C D B A D C B