Preferred Label : prochirality;
IUPAC definition : the term prochirality is also applied to the enantiotopic faces of a trigonal system.; the term prochiral also applies to a tetrahedral atom of an achiral or chiral molecule
which is bonded to two stereoheterotopic groups. for example, the prochiral molecule
ch3ch2ohcan be converted into the chiral molecule ch3chdoh by the isotopic replacement
of one of the two enantiotopic hydrogen atoms of the methylene group. the carbon atom
of the methylene group is called prochiral. the prochiral molecule ho2cch2chohch2co2h
can be converted into a chiral product byesterification of one of the two enantiotopic
1ch2co2h groups. the carbon atom of the choh group is called prochiral. the chiral
molecule ch3chohch2ch3 can be converted into one of the diastereoisomers of ch3chohchdch3
by the isotopic replacement of one of the two diastereotopic hydrogen atoms of the
methylene group. the carbon atom of the methylene group is called prochiral. the stereoheterotopic
groups in these cases may be described as pro-r or pro-s. reference to the two stereoheterotopic
groups themselves as prochiral, although common, is strongly discouraged. chirality
centre; the term prochirality also applies to an achiral molecule or entity which contains
a trigonal system and which can be made chiral by the addition to the trigonal system
of a new atom or achiral group. for example addition of hydrogen to one of the enantiotopic
faces of the prochiral ketone ch3ch2coch3 gives one of the enantiomers of the chiral
alcohol ch3ch2chohch3; the addition of cn-1 to one of the diastereotopic faces of
the chiral aldehyde shown below converts it into one of the diastereoisomers of the
cyanohydrin. the two faces of the trigonal system may be described as re and si.; the geometric property of an achiral object (or spatial arrangement of points or atoms)
which is capable of becoming chiral in a single desymmetrization step. an achiral
molecular entity, or a part of it considered on its own, is thus called prochiral
if it can be made chiral by the replacement of an existing atom (or achiral group)
by a different one. an achiral object which is capable of becoming chiral in two desymmetrization
steps is sometimes described as proprochiral. for example the proprochiral ch3co2h
becomes prochiral as ch2dco2h and chiral as chdtco2h.;
Origin ID : P04859;
See also
the term prochirality is also applied to the enantiotopic faces of a trigonal system.
the term prochiral also applies to a tetrahedral atom of an achiral or chiral molecule
which is bonded to two stereoheterotopic groups. for example, the prochiral molecule
ch3ch2ohcan be converted into the chiral molecule ch3chdoh by the isotopic replacement
of one of the two enantiotopic hydrogen atoms of the methylene group. the carbon atom
of the methylene group is called prochiral. the prochiral molecule ho2cch2chohch2co2h
can be converted into a chiral product byesterification of one of the two enantiotopic
1ch2co2h groups. the carbon atom of the choh group is called prochiral. the chiral
molecule ch3chohch2ch3 can be converted into one of the diastereoisomers of ch3chohchdch3
by the isotopic replacement of one of the two diastereotopic hydrogen atoms of the
methylene group. the carbon atom of the methylene group is called prochiral. the stereoheterotopic
groups in these cases may be described as pro-r or pro-s. reference to the two stereoheterotopic
groups themselves as prochiral, although common, is strongly discouraged. chirality
centre
the term prochirality also applies to an achiral molecule or entity which contains
a trigonal system and which can be made chiral by the addition to the trigonal system
of a new atom or achiral group. for example addition of hydrogen to one of the enantiotopic
faces of the prochiral ketone ch3ch2coch3 gives one of the enantiomers of the chiral
alcohol ch3ch2chohch3; the addition of cn-1 to one of the diastereotopic faces of
the chiral aldehyde shown below converts it into one of the diastereoisomers of the
cyanohydrin. the two faces of the trigonal system may be described as re and si.
the geometric property of an achiral object (or spatial arrangement of points or atoms)
which is capable of becoming chiral in a single desymmetrization step. an achiral
molecular entity, or a part of it considered on its own, is thus called prochiral
if it can be made chiral by the replacement of an existing atom (or achiral group)
by a different one. an achiral object which is capable of becoming chiral in two desymmetrization
steps is sometimes described as proprochiral. for example the proprochiral ch3co2h
becomes prochiral as ch2dco2h and chiral as chdtco2h.