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erythro and threo isomers

dhiren chhetrapal , 13 Years ago

Grade 12th Pass

4 Answers

Rahul Kumar

Last Activity: 13 Years ago

Two common prefixes used to distinguish diastereomers are threo and erythro (which correspond to the more intuitive syn and anti labels, respectively). When drawn in the Fischer projection the erythro isomer has two identical substituents on the same side and the threo isomer has them on opposite sides. When drawn as a zig-zag chain, the erythro isomer has two identical substituents on different sides of the plane (anti). The names are derived from the diastereomeric aldoses erythrose (a syrup) and threose (melting point 126 °C).

dhiren chhetrapal

Last Activity: 13 Years ago

plz expain with structure....

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Last Activity: 7 Years ago

erythro threo nomenclature is valid when a molecule obeys following conditions

1)have only two assymetric carbon.

2)both assymetric carbons should be consecutive.

3)both carbon have 2 groups simmilar and third group different.

if all conditions are satisfied then you have to just make fisscer projection formula of compound by placing the different groups which is attached to assymetric carbon in vertical line the if the simmilar groups of respective assymetric carbon are on same side then of vertical line then it is erythro otherwise threo.

hope my answer will help.:)

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Last Activity: 7 Years ago

you can also prefer march’s advanced organic chemistry book download its pdf and search for erythro threo nomenclature in subject index thereeyou will get it with examples