Erythro and Threo Terms used for diastereomers with two adjacent chiral C's,without symmetric ends For symmetric molecules,use meso or d,/. CH2CH3 CH2CH3 COOH COOH H Br Br H H OH H OH H Br H Br H OH HO H CH3 CH3 COOH COOH erythro threo meso (d,l) 2,3-dibromopentane tartaric acid => Chapter 23 7 Chapter 23 7 Erythro and Threo • Terms used for diastereomers with two adjacent chiral C’s, without symmetric ends. • For symmetric molecules, use meso or d,l. =>