كيمياء عضوية - محاضرة 10 (PDF)

ORGANIC CHEMISTRY lecture 10 1/7 :‫اﻟﻜﻴﻤﻴﺎء اﻟﻤﺠﺴﻤﺔ‬ Stereochemistry and stereoisomer ‫ﻫﻲ اﻟﻌﻠﻢ اﻟﺬي‬ Stereochemistry : is the science th...

ORGANIC CHEMISTRY lecture 10 1/7 :‫اﻟﻜﻴﻤﻴﺎء اﻟﻤﺠﺴﻤﺔ‬ Stereochemistry and stereoisomer ‫ﻫﻲ اﻟﻌﻠﻢ اﻟﺬي‬ Stereochemistry : is the science that deals with structure in three ‫ﻳﺘﻌﺎﻣﻞ ﻣﻊ اﻟﺘﺮﻛﻴﺐ‬ ‫ﻓﻲ ﺛﻼﺛﺔ أﺑﻌﺎد‬ dimensions. ‫ ﻣﺮﻛﺒﺎت‬:‫اﻻﻳﺰوﻣﺮات‬ Isomers : are different compounds that have the same molecular ‫ﻣﺨﺘﻠﻔﺔ ﻟﻬﺎ ﻧﻔﺲ اﻟﺼﻴﻐﺔ‬ ‫اﻳﺰوﻣﺮات ﺻﻮرة‬ formula.which are called structural isomers. ‫اﻟﺠﺰﻳﺌﻴﺔ واﻟﺘﻲ ﺗﺴﻤﻰ‬ ‫ ﻫﺬه‬.‫ﻣﻌﻜﻮﺳﺔ‬.‫اﻻﻳﺰوﻣﺮات اﻟﻬﻴﻜﻠﻴﺔ‬ Steroisomer : is the particular kind of isomers that are different from each ‫اﻻﻳﺰوﻣﺮات ﻟﻬﺎ ﻧﻔﺲ‬ ‫اﻟﺨﺼﺎﺋﺺ اﻟﻔﻴﺰﻳﺎﺋﻴﺔ‬ other only is the way of orientation of atoms is space. ‫ ﻫﻮ ﻧﻮع‬:‫اﻷﻳﺰوﻣﺮ اﻟﻤﺠﺴﻢ‬ Enantiomers : is the mirror image isomers. These isomers have the same ‫ﺧﺎص ﻣﻦ اﻷﻳﺰوﻣﺮات اﻟﺘﻲ‬ ‫ﺑﺎﺳﺘﺜﻨﺎء دوران‬ ‫ﺗﺨﺘﻠﻒ ﻋﻦ ﺑﻌﻀﻬﺎ اﻟﺒﻌﺾ‬ ‫اﻟﻀﻮء اﻟﻤﺴﺘﻘﻄﺐ‬ physical properties except the rotation of the plane polarized light. ‫ﻓﻘﻂ ﻃﺮﻳﻘﺔ ﺗﻮﺟﻴﻪ اﻟﺬرات‬ ‫اﻟﻤﺴﺘﻮي‬. They are differ only in the way of orientation of the atoms in space.They.‫ﻫﻲ اﻟﻔﻀﺎء‬ ‫ﺗﻮﺟﻴﻪ اﻟﺬرات ﻓﻲ‬ are not superimposable to each other. The non superimposability of ‫ وﻻ ﻳﻤﻜﻦ‬، ‫اﻟﻔﻀﺎء‬ mirror image leads to enantiomer and also gives each of them their.‫ﺗﺮاﻛﺐ ﺑﻌﻀﻬﺎ ﻣﻊ ﺑﻌﺾ‬ ‫ﻳﺆدي ﻋﺪم ﻗﺎﺑﻠﻴﺔ‬ optical activity. ‫اﻟﺼﻮرة اﻟﻤﻌﻜﻮﺳﺔ‬ (enantio =opposite ) for example , biochemical compound for leucine ‫ﻟﻠﺘﺮاﻛﺐ إﻟﻰ ﺗﻜﻮﻳﻦ‬ ‫اﻷﻳﺰوﻣﺮات اﻟﻬﻴﻜﻠﻴﺔ ﻟﻬﺎ‬ ‫ﻣﺘﻤﺎﺛﻞ وﻳﻌﻄﻲ ﻛﻞ ﻣﻨﻬﺎ‬ ‫ﺧﺼﺎﺋﺺ ﻓﻴﺰﻳﺎﺋﻴﺔ‬.‫ﻧﺸﺎﻃﻪ اﻟﺒﺼﺮي‬ Chiral compound :-.MP ، b.p ‫ﻣﺨﺘﻠﻔﺔ ﻓﻲ‬ (‫ = اﻟﻌﻜﺲ‬enantio) The structural isomers have different physical properties in M.P , b.p. ‫ﻛﺜﺎﻓﺔ اﻻﻳﺰوﻣﺮات ﻟﻬﺎ‬ ، ‫ﻋﻠﻰ ﺳﺒﻴﻞ اﻟﻤﺜﺎل‬ ‫ﺧﺼﺎﺋﺺ ﻣﺘﻄﺎﺑﻘﺔ ﻳﺠﺐ‬ ‫ﻣﺮﻛﺐ ﻛﻴﻤﻴﺎﺋﻲ ﺣﻴﻮي‬ density ‫أن ﻳﻜﻮن ﻟﻬﺎ ﻧﻔﺲ‬ ‫ﻟﻠﻴﻮﺳﻴﻦ‬ If the isomers have identical properties it must have identical molecular.‫اﻟﺘﺮﻛﻴﺐ اﻟﺠﺰﻳﺌﻲ‬ structure. It was discovered big number of compounds which contradict this fact Consider the compound leucine C6H13O2N. this compound present as two isomers ‫ﺗﻢ اﻛﺘﺸﺎف ﻋﺪد ﻛﺒﻴﺮ ﻣﻦ اﻟﻤﺮﻛﺒﺎت اﻟﺘﻲ ﺗﺘﻌﺎرض ﻣﻊ ﻫﺬه‬ ‫اﻟﺤﻘﻴﻘﺔ ﻣﻊ اﻷﺧﺬ ﺑﻌﻴﻦ اﻻﻋﺘﺒﺎر ﻣﺮﻛﺐ ﻟﻴﺴﻴﻦ‬ H3C CH3 ‫ ﻫﺬا اﻟﻤﺮﻛﺐ ﻣﻮﺟﻮد ﻓﻲ ﺻﻮرة اﺛﻨﻴﻦ ﻣﻦ‬.C6H13O2N CH ‫اﻻﻳﺰوﻣﺮات‬ ، ‫ﺗﺨﺘﻠﻒ ﻫﺬه اﻷﻳﺰوﻣﺮات ﻓﻲ اﻟﺬوق‬ ‫اﻷول ﻟﻪ ﻃﻌﻢ ﻣﺮ واﻵﺧﺮ ﻟﻪ ﻃﻌﻢ‬ CH2 ‫ ﻷﻧﻬﺎ‬.‫ﻋﺮق ﻷﻧﻬﻤﺎ أﻳﺰوﻣﺮات ﻣﺨﺘﻠﻔﺔ‬ H C CO 2H ‫ﺗﺨﺘﻠﻒ ﻓﻲ اﺗﺠﺎه اﻟﺬرات ﻓﻲ اﻟﻔﻀﺎء‬ Chiral atom NH2 These isomers are differ in taste , the first has bitter taste and the other has sweat taste because they are different isomers. because they are differ in orientation of atoms in space ‫ﻫﻴﻜﻞ‬- :‫ﻣﺮﻛﺒﺎن‬ ‫ﺛﻼﺛﻲ اﻷﺑﻌﺎد ﻣﻦ‬ NH2 CO2H ‫اﻷﻳﺰوﻣﺮ اﻻﺳﺘﺮﻳﻮ‬ CO2H NH2 ‫ﻟﻴﺴﻴﻦ ﻣﺮﺗﺒﻄﺎن‬ H C H C ‫ﺑﻄﺮﻳﻘﺔ ﻣﻬﻤﺔ ﺑﺤﻴﺚ‬ CH2CH (CH3)2 CH2CH (CH3)2 ‫ﺗﻜﻮن ﺻﻮرة‬ ‫ ﻣﻌﻜﻮﺳﺔ ﻟﺒﻌﻀﻬﺎ‬Two compounds:-three dimensional structure of leucine ‫ ﻋﻼوة ﻋﻠﻰ‬.‫ اﻟﺒﻌﺾ‬Stereoisomer are related in an important way that they are mirror-image ‫ ﻻ ﻳﺘﻢ ﻓﺮض‬، ‫ ذﻟﻚ‬of each other. ‫ اﻟﻤﺰﻳﺪ ﻣﻦ ﻫﺬه‬Further more these mirror-image are not superimposed ‫اﻟﺼﻮرة اﻟﻤﺮآة‬ 1  ORGANIC CHEMISTRY lecture 10 2/7 NH2 NH2 ‫ﻋﻼﻗﺔ ﺻﻮرة ﻣﻌﻜﻮﺳﺔ‬ CO2H HO 2C ‫ﻻﺛﻨﻴﻦ ﻣﻦ اﻷﻳﺰوﻣﺮات‬ H C C H ‫ﻧﺤﻦ‬.‫اﻟﻔﺮاﻏﻴﺔ ﻟﻠﻠﻴﺴﻴﻦ‬ ‫ﻣﺘﻤﺎﺛﻠﻮن ﻧﺘﺬﻛﺮ أن ﺟﻤﻴﻊ‬ CH2CH (CH3)2 (CH3)2CHCH2 ‫اﻟﻜﺎﺋﻨﺎت ﻟﻬﺎ ﺻﻮرة‬ Leucine ، ‫ وﻣﻊ ذﻟﻚ‬.‫ﻣﻌﻜﻮﺳﺔ‬ Mirror-image relationship of the two stereoisomers of lecine.We them ‫ﻳﻤﻜﻦ ﺗﺮﻛﻴﺐ اﻷﺷﻴﺎء ﻋﻠﻰ‬ enantiomers ‫ ﻛﻴﻒ ﻧﻤﻴﺰ‬.‫ﺻﻮرﺗﻬﺎ اﻟﻤﺮآة‬ Remember that all objects have a mirror image. However objects can be ‫ﺑﻴﻦ اﻟﻤﺮﻛﺒﺎت اﻟﻠﻮﻟﺒﻴﺔ‬ ً‫واﻟﻤﺮﻛﺒﺔ اﻟﻼﻳﺮﻗﻴﺔ أوﻻ‬ superimposed on their mirror image ‫ﻳﺠﺐ أن ﻧﺤﺪد ﻣﺎ إذا‬ How we distinguish between chiral and achiral compounds ‫ﻛﺎﻧﺖ ﻫﺬه اﻷﻳﺰوﻣﺮات‬ First we must determined whether this isomers superimposed or not ‫ﻣﺘﺮاﻛﺒﺔ أم ﻻ ﻣﺮﻛﺐ‬ Chiral compound :- any compound which has one or more carbon atoms ‫ أي ﻣﺮﻛﺐ‬- :‫ﻣﺮاوان‬ ‫ذرة اﻟﻜﺮﺑﻮن اﻟﻠﻮﻟﺒﻴﺔ ﻫﻲ‬ bonded to four different atoms or groups ‫ﻛﺮﺑﻮن‬ ‫ﻳﺤﺘﻮي ﻋﻠﻰ ذرة‬.‫ذرة ﻏﻴﺮ ﻣﺘﻨﺎﻇﺮة‬ ‫واﺣﺪة أو أﻛﺜﺮ ﻣﺮﺗﺒﻄﺔ‬ chirality ‫اﻻﺧﺘﻼف ﺑﻴﻦ‬ ‫ﺑﺄرﺑﻊ ذرات أو ﻣﺠﻤﻮﻋﺎت‬ :‫واﻟﻨﺸﺎط اﻟﺒﺼﺮي‬ ‫ﻣﺨﺘﻠﻔﺔ‬ ‫ اﻷﺷﻴﺎء اﻟﺘﻲ‬:chirality Cl NH2 ‫ﻫﻲ ﺻﻮر ﻣﻌﻜﻮﺳﺔ وﻟﻜﻦ‬ H3C * * * ‫ اﻟﻨﺸﺎط‬، ‫ﻏﻴﺮ ﻣﺘﺮاﻛﺒﺔ‬ CH CH CH3 CH3 CH2 CH CH3 CH CO2H ‫اﻟﺒﺼﺮي ﻫﻮ ﺧﺎﺻﻴﺔ‬ H3C ‫ﻓﻴﺰﻳﺎﺋﻴﺔ ﻳﻘﻮم ﻓﻴﻬﺎ‬ Cl ‫اﻟﻤﺮﻛﺐ ﺑﺘﺪوﻳﺮ اﻟﻀﻮء‬.‫اﻟﻤﺴﺘﻘﻄﺐ اﻟﻤﺴﺘﻮي‬ The chiral carbon atom is un symmetrical atom. The different between chirality and optical activity : chirality : objects which are mirror images but not superimposed , optical activity is a physical property in which the compound which rotate the plane polarized light. ‫إذا ﻛﺎن اﻟﻤﺮﻛﺐ ﻳﺘﺄﻟﻒ ﻣﻦ‬ ، ‫اﺛﻨﻴﻦ ﻣﻦ اﻟﻤﺘﺸﺎﻫﺪﻳﻦ‬ If the compound composed from two enantiomers i.e. one of them (-) and ‫( واﻵﺧﺮ ﻫﻮ‬-) ‫ أي أﺣﺪﻫﻤﺎ‬the other is (+) the net rotation = zero = ‫( ﺻﺎﻓﻲ اﻟﺪوران‬+) A mixture of equal amount of two enantiomers is called racemic mixture , ‫ ﺻﻔﺮ ﻳﺴﻤﻰ ﺧﻠﻴﻂ ﻣﻦ‬it is optically inactive ‫ﻛﻤﻴﺔ ﻣﺘﺴﺎوﻳﺔ ﻣﻦ‬ Example ‫ﻣﺘﺸﺎﻫﺪﻳﻦ ﺧﻠﻴﻂ‬ ‫ ﻓﻬﻮ ﻏﻴﺮ ﻧﺸﻂ‬، ‫ راﺳﻴﻤﻲ‬The light-catalyzed butane and chlorination of to form 2-chlorobutane as ‫ ﺑﺼﺮﻳً ﺎ‬one the product. ‫ﻛﻠﻮروﺑﻮﺗﺎن ﻛﺄﺣﺪ‬-2 ‫ﻣﺜﺎل اﻟﺒﻮﺗﺎن اﻟﻤﺤﻔﺰ ﺑﺎﻟﻀﻮء واﻟﻜﻠﻮر ﻟﺘﻜﻮﻳﻦ‬.‫اﻟﻤﻨﺘﺠﺎت‬ CH2CH3 CH2CH3 light H H CH3 CH2 CH2 CH3 + Cl2 C Cl + Cl C CH3 CH3 2-chloro butane contain chiral carbon but it is inactive because equal amounts of dextrorotatory and levorotatory isomers are formed in equal amount. ‫ﻳﺤﺘﻮي ﻛﻠﻮرو اﻟﺒﻮﺗﺎن ﻋﻠﻰ ﻛﺮﺑﻮن ﻣﺮاوان وﻟﻜﻨﻪ ﻏﻴﺮ ﻧﺸﻂ ﻷن ﻛﻤﻴﺎت ﻣﺘﺴﺎوﻳﺔ ﻣﻦ أﻳﺰوﻣﺮات‬.‫ﺗﻜﺴﻴﺮ وﺗﺮاﻛﻢ ﺗﺘﺸﻜﻞ ﺑﻜﻤﻴﺎت ﻣﺘﺴﺎوﻳﺔ‬ 2  ORGANIC CHEMISTRY lecture 10 ‫ﻧﺸﻄﺎ ﺑﺼﺮﻳً ﺎ وﻫﺬا‬ ً ‫ وﺳﻴﻜﻮن اﻟﻤﺮﻛﺐ‬، ‫واﺣﺪً ا ﻓﻘﻂ ﻣﻦ اﻟﻤﺘﻐﻴﺮات‬3/7 ‫ ﺳﻴﻨﺘﺞ اﻟﺘﻔﺎﻋﻞ‬، ‫ﻓﻲ اﻟﻨﻈﺎم اﻟﺤﻲ‬.‫ ورد اﻟﻔﻌﻞ ﻳﺤﺪث ﻓﻲ اﻟﻨﻈﺎم اﻟﺤﻲ‬.‫ﻫﻮ اﻻﺧﺘﻼف اﻟﺮﺋﻴﺴﻲ ﺑﻴﻦ اﻟﺘﻔﺎﻋﻞ اﻟﺬي ﻳﺤﺪث ﻓﻲ اﻟﻤﺨﺘﺒﺮ‬ In living system The reaction will produce only one of the enantiomers ,the compound will be optically active and this is the main different between reaction occurs in lab. and reaction occurs in living system. ‫ﺗﺴﻤﻴﺔ اﻷﻳﺰوﻣﺮات‬ ‫اﻟﻔﺮاﻏﻴﺔ ﻳﺠﺐ أن ﻧﺬﻛﺮ‬ Naming of stereoisomers we must mention the specific rotation of ‫اﻟﺪوران اﻟﻤﺤﺪد‬ conferbration ‫ﻟﻠﻜﻮﻧﻔﺪراﻟﻴﺔ‬ Diasteroisomers :- The compound which contain two or more chiral centers can exist as more than two sreroisomers. They are not mirror images and not superimposable. ‫ اﻟﺤﺪ‬- :‫ﻗﺎﻋﺪة ﻋﺎﻣﺔ‬ General rule :- the maximal number of stereoisomers is 2n ‫اﻷﻗﺼﻰ ﻟﻌﺪد اﻷﻳﺰوﻣﺮات‬ ‫ = ﻋﺪد‬2n n ‫اﻟﻔﺮاﻏﻴﺔ ﻫﻮ‬ n= number of chiral atoms ‫ ﻳﻤﻜﻦ أن ﻳﻮﺟﺪ‬:‫اﻷﻳﺰوﻣﺮات اﻻﻧﺸﻄﺎرﻳﺔ‬ ‫اﻟﺬرات اﻟﻠﻮﻟﺒﻴﺔ‬ * * ‫اﻟﻤﺮﻛﺐ اﻟﺬي ﻳﺤﺘﻮي ﻋﻠﻰ ﻣﺮﻛﺰﻳﻦ أو أﻛﺜﺮ‬ CH3 CH CH CH CH3 ‫ﻣﻦ اﻟﻤﺮاﻛﺰ اﻟﻠﻮﻟﺒﻴﺔ ﻓﻲ ﺷﻜﻞ أﻛﺜﺮ ﻣﻦ اﺛﻨﻴﻦ‬ OH OH OH ‫ إﻧﻬﺎ ﻟﻴﺴﺖ ﺻﻮ ًرا‬.‫ﻣﻦ اﻷﻳﺰوﻣﺮات اﻟﻔﺮاﻏﻴﺔ‬ ‫ﻣﺜﺎل ﻋﻠﻰ ﻣﺮﻛﺐ ﻳﺤﺘﻮي‬ ‫ﻋﻠﻰ ﻣﺮﻛﺰﻳﻦ ﻟﻮﻟﺒﻴﻴﻦ ﻫﻮ‬ 2 chirals.‫ﻣﻌﻜﻮﺳﺔ وﻟﻴﺴﺖ ﻗﺎﺑﻠﺔ ﻟﻠﺘﺮﻛﻴﺐ‬ ‫اﻟﻜﺮﺑﻮﻫﻴﺪرات‬ example of compound containing two chiral centers is the carbohydrate ‫ﺛﻼﺛﻲ‬-2،3،4 ‫ﻫﻴﺪروﻛﺴﻲ‬ 2,3,4-trihydroxybutyraldehyde ‫ﺑﻮﺗﻴﺮاﻟﺪﻳﻬﺎﻳﺪ‬ * * HOCH2 CH CH CHO OH OH It has four stereoisomers CHO CHO HO C H H C OH HO C H H C OH CH2OH CH2OH I II L-erythrose D-erythrose They are pair of enantiomers called Erythose CHO CHO H C OH HO C H HO C H H C OH CH2OH CH2OH III IV L-thereose D-thereose 3  ORGANIC CHEMISTRY lecture 10 4/7 These pair of enantiomers called Threose I & II are mirror image and they are not superimposed III & IV are mirror image and they are not superimposed ( Ι , ΙΙΙ ), ( ΙΙ , Ιv) the compounds are not mirror image (Diastereomers ) and not superimposable ‫ ﻫﻲ‬Threose I & II ‫ﻫﺬان اﻟﺰوﺟﺎن ﻣﻦ اﻟﻤﺘﻐﻴﺮات اﻟﺘﻲ ﺗﺴﻤﻰ‬ Diastereomers have different physical properties ‫ ﻫﻲ ﺻﻮرة ﻣﻌﻜﻮﺳﺔ‬IV ‫ و‬III ‫ﺻﻮرة ﻣﻌﻜﻮﺳﺔ وﻟﻴﺴﺖ ﻣﺘﺮاﻛﺒﺔ‬ ‫( اﻟﻤﺮﻛﺒﺎت ﻟﻴﺴﺖ ﺻﻮرة‬ΙΙ ، Ιv) ، (Ι ، ΙΙΙ) ‫وﻟﻴﺴﺖ ﻣﺘﺮاﻛﺒﺔ‬ Ι is liquid ‫( وﻟﻴﺴﺖ دﻳﺎﺳﺘﻴﺮﻳﻮﻣﺮات ﻗﺎﺑﻠﺔ‬Diastereomers) ‫ﻣﻌﻜﻮﺳﺔ‬ ‫ﻗﺎﺑﻠﻴﺔ اﻟﺬوﺑﺎن‬ Ιv is solid ‫ ﺻﻠﺐ‬Ιv ‫ ﺳﺎﺋﻞ‬Ι ‫ﻟﻠﺘﺮﻛﻴﺐ ﻟﻬﺎ ﺧﺼﺎﺋﺺ ﻓﻴﺰﻳﺎﺋﻴﺔ ﻣﺨﺘﻠﻔﺔ‬ ‫ ﻗﺎﺑﻞ‬Erythrose Solubility ‫ﻟﻠﺬوﺑﺎن ﺑﺪرﺟﺔ ﻋﺎﻟﻴﺔ‬ ‫ﻓﻲ اﻹﻳﺜﺎﻧﻮل ﺑﻴﻨﻤﺎ‬ Erythrose highly soluble in ethanol while Threose slightly soluble in ‫ ﻗﺎﺑﻞ‬Threose ethanol ‫ﻟﻠﺬوﺑﺎن ﺑﺸﻜﻞ‬ ‫ﻃﻔﻴﻒ ﻓﻲ اﻹﻳﺜﺎﻧﻮل‬ Meso stereoisomers :- Certain molecules that contain two chiral atoms do not exist as four stereoisomers. ‫ ﺟﺰﻳﺌﺎت ﻣﻌﻴﻨﺔ ﺗﺤﺘﻮي ﻋﻠﻰ ذرﺗﻴﻦ ﻻ ﺗﺘﻮاﺟﺪ ﻛﺄرﺑﻌﺔ إﻳﺰوﻣﺮات‬:‫اﻷﻳﺰوﻣﺮات اﻟﻤﺘﻮﺳﻄﺔ‬ Specific example is Tartaric acid ‫ ﻣﺜﺎل ﻣﺤﺪد ﻫﻮ ﺣﻤﺾ اﻟﻄﺮﻃﺮﻳﻚ‬.‫ﻣﺠﺴﻤﺔ‬ OH * HO2C CH CH CO2H * OH CO2H CO2H CO2H CO2H H C OH HO C H H C OH OH H C OH HO C H H C OH H C OH H OH C OH CO2H CO2H CO2H CO2H pair of enantiomers identical compound they are called mesoisomers CO2H CO2H H C OH rotation 180 HO C H H C OH HO C H CO2H CO2H III IV Mesoisomers is optically inactive because they have plane of symmetry. it superimposed on its mirror image ‫ ﻳﺘﻢ ﻓﺮﺿﻪ ﻋﻠﻰ‬.‫اﻷﻳﺰوﻣﺮات اﻟﻤﺘﻮﺳﻄﺔ ﻏﻴﺮ ﻧﺸﻄﺔ ﺑﺼﺮﻳً ﺎ ﻷن ﻟﻬﺎ ﻣﺴﺘﻮى ﻣﻦ اﻟﺘﻨﺎﻇﺮ‬ ‫ﺻﻮرﺗﻪ اﻟﻤﺮآة‬ 4  ‫ﻗﺮار ﺣﻞ اﻟﺨﻠﻴﻂ‬ ‫ ﻫﻮ ﻋﻤﻠﻴﺔ‬Racemic ORGANIC CHEMISTRY lecture 10 ‫ﻓﺼﻞ اﻟﻤﺘﻤﺎﺛﻼت إﻟﻰ‬ 5/7 ‫ﻣﺠﺴﻢ ﻣﺠﺴﻢ ﻧﻘﻲ‬ Resolution of Racemic mixture Resolution is process of separating of enantiomers into pure stereoisomer 1- mechanical separation :- it was performed by Pasteur when he crystallize tartaric acid salt he found two types of crystals : :‫ أﺟﺮاه ﺑﺎﺳﺘﻴﺮ ﻋﻨﺪﻣﺎ ﺑﻠﻮر ﻣﻠﺢ ﺣﻤﺾ اﻟﻄﺮﻃﺮﻳﻚ وﺟﺪ ﻧﻮﻋﻴﻦ ﻣﻦ اﻟﺒﻠﻮرات‬:‫اﻟﻔﺼﻞ اﻟﻤﻴﻜﺎﻧﻴﻜﻲ‬ a- crystals which are dextrorolotary ‫ اﻟﺒﻠﻮرات اﻟﺘﻲ ﺗﻜﻮن ﻣﺰﻋﺠﺔ‬-‫أ‬ ‫أي ﻣﺮﻛﺐ ﻟﻪ ﻣﺴﺘﻮى ﺗﻨﺎﻇﺮ ﻫﻮ ﻏﻴﺮ‬ b- crystals which are levorototary ‫ ﺑﻠﻮرات ﻟﻴﻔﻮروﺗﺎري‬-‫ب‬ ‫ﻧﺸﻂ ﺑﺼﺮﻳًﺎ ﻳﻤﻜﻨﻪ ﻓﺼﻠﻬﺎ‬ ‫)ﺑﺎﺳﺘﺨﺪام زوج ﻣﻦ اﻟﻤﻠﻘﻂ‬ any compound has plane of symmetry is optical inactive ‫وﻋﺪﺳﺔ ﻣﻜﺒﺮة( ﺑﻴﻦ ﺑﻠﻮرات اﻟﻴﺪ‬ he has able to separate them (by using a pair of tweezers and magniting ‫اﻟﻴﻤﻨﻰ وﺑﻠﻮرات اﻟﻴﺪ اﻟﻴﺴﺮى‬ lens ) between right handed crystals and left handed crystals :‫ اﻟﻔﺼﻞ اﻹﻧﺰﻳﻤﻲ‬- 2- Enzymetic separation :- ‫ﻳﻤﻜﻦ أن ﻳﺘﻢ ﻫﺬا‬ this separation can be done in living system , The living system react with ‫اﻟﻔﺼﻞ ﻓﻲ اﻟﻨﻈﺎم‬ one of the enantiomers and leaving the other. ‫ ﻳﺘﻔﺎﻋﻞ اﻟﻨﻈﺎم‬، ‫اﻟﺤﻲ‬ ‫اﻟﺤﻲ ﻣﻊ أﺣﺪ‬ Pasture found that a yeast in urine reacted with (+) tartaric acid when he ‫اﻟﻤﺘﺸﺎﻫﺪﻳﻦ وﻳﺘﺮك‬ gave the yeast racemic tartaric acid he found that only the dextrorotatory ‫ وﺟﺪ اﻟﻤﺮﻋﻰ‬.‫اﻵﺧﺮ‬ isomer was consumed , The levorotatory isomers was isolated at the end ‫أن ﺧﻤﻴﺮة ﻓﻲ اﻟﺒﻮل‬ of the reaction (+) ‫ﺗﻔﺎﻋﻠﺖ ﻣﻊ‬ 3- Separating diastereomers ‫ﺣﻤﺾ اﻟﻄﺮﻃﺮﻳﻚ‬ ‫ﻋﻨﺪﻣﺎ أﻋﻄﻰ اﻟﺨﻤﻴﺮة‬ diastereomers have different physical properties , This fact provides us a ‫ﺣﻤﺾ اﻟﻄﺮﻃﺮﻳﻚ‬ method of resolving a racemic mixture , by reacting of a racemic mixture ‫اﻟﺮاﺳﻴﻤﻲ وﺟﺪ أﻧﻪ ﺗﻢ‬ with an optically active reagent - diastereomers ‫ ﻫﺬه‬، ‫ﻣﻨﻔﺼﻠﺔ ﻟﻬﺎ ﺧﺼﺎﺋﺺ ﻓﻴﺰﻳﺎﺋﻴﺔ ﻣﺨﺘﻠﻔﺔ‬ ‫اﺳﺘﻬﻼك اﻷﻳﺰوﻣﻴﺮ‬ ‫ ﻋﻦ ﻃﺮﻳﻖ ﺗﻔﺎﻋﻞ‬، ‫اﻟﺤﻘﻴﻘﺔ ﺗﻮﻓﺮ ﻟﻨﺎ ﻃﺮﻳﻘﺔ ﻟﺤﻞ ﺧﻠﻴﻂ راﺳﻴﻤﻲ‬ ‫ وﺗﻢ ﻋﺰل‬، ‫ﻓﻘﻂ‬ ‫ﺧﻠﻴﻂ راﺳﻴﻤﻲ ﻣﻊ ﻛﺎﺷﻒ ﻧﺸﻂ ﺑﺼﺮﻳﺎ‬ ‫أﻳﺰوﻣﺮات ﻃﺮﻃﺮﻳﻚ‬ Specification of configuration: R and S Now, a further problem arises. How can we specify a particular ‫ و‬R :‫ﻣﻮاﺻﻔﺎت اﻟﺘﻜﻮﻳﻦ‬ ‫ﻓﻲ ﻧﻬﺎﻳﺔ اﻟﺘﻔﺎﻋﻞ‬ ‫ ﺗﻨﺸﺄ ﻣﺸﻜﻠﺔ‬، ‫ اﻵن‬S configuration ‫ ﻛﻴﻒ ﻳﻤﻜﻨﻨﺎ‬.‫أﺧﺮى‬ in some simpler, more convenient way than by always having to draw its ‫ﺗﺤﺪﻳﺪ ﺗﻜﻮﻳﻦ ﻣﻌﻴﻦ‬ picture? ‫ﺑﻄﺮﻳﻘﺔ أﺑﺴﻂ وأﻛﺜﺮ‬ The most generally useful way yet suggested is the use of the prefixes R ‫ﻣﻼءﻣﺔ ﻣﻦ اﻻﺿﻄﺮار‬ and S. ‫داﺋﻤﺎ إﻟﻰ رﺳﻢ ﺻﻮرﺗﻪ؟‬ ً According to a procedure proposed by R. S. Cahn (The Chemical Society, ‫اﻟﻄﺮﻳﻘﺔ اﻷﻛﺜﺮ ﻓﺎﺋﺪة‬ ‫واﻟﺘﻲ ﺗﻢ اﻗﺘﺮاﺣﻬﺎ ﺣﺘﻰ‬ London), ‫اﻵن ﻫﻲ اﺳﺘﺨﺪام‬ ‫ ﺑﺎﺗﺒﺎع‬.1 ‫اﻟﺨﻄﻮة‬ Step 1. Following a set of sequence rules, we assign a sequence of ً.S ‫ و‬R ‫اﻟﺒﺎدﺋﺎت‬ ‫وﻓﻘﺎ‬ ‫ﻣﺠﻤﻮﻋﺔ ﻣﻦ ﻗﻮاﻋﺪ‬ priority to the four atoms or groups of atoms attached to the chiral center. R. ‫ﻟﻺﺟﺮاء اﻟﺬي اﻗﺘﺮﺣﻪ‬ ‫ ﻧﺨﺼﺺ‬، ‫اﻟﺘﺴﻠﺴﻞ‬ In the case of CHClBrI, for example, the four atoms attached to the chiral S. Cahn (The ً ‫ﺗﺴﻠﺴﻼ ﻟﻸوﻟﻮﻳﺔ ﻟﻠﺬرات‬ Chemical Society ، ‫اﻷرﺑﻊ أو ﻣﺠﻤﻮﻋﺎت‬ center are all different and priority depends simply on atomic number, the ، London) ‫اﻟﺬرات اﻟﻤﺮﺗﺒﻄﺔ ﺑﺎﻟﻤﺮﻛﺰ‬ atom ‫ ﻓﻲ ﺣﺎﻟﺔ‬.‫اﻟﻠﻮﻟﺒﻲ‬ of higher number having higher priority. Thus I, Br, CI, H. ‫ ﻋﻠﻰ ﺳﺒﻴﻞ‬، CHClBrI ‫ ﺗﻜﻮن اﻟﺬرات‬، ‫اﻟﻤﺜﺎل‬ ‫اﻷرﺑﻊ اﻟﻤﺮﺗﺒﻄﺔ ﺑﺎﻟﻤﺮﻛﺰ‬ ‫اﻟﻠﻮﻟﺒﻲ ﻣﺨﺘﻠﻔﺔ وﺗﻌﺘﻤﺪ‬ ‫اﻷوﻟﻮﻳﺔ ﺑﺒﺴﺎﻃﺔ ﻋﻠﻰ‬ ‫ ذرة اﻟﻌﺪد‬، ‫اﻟﻌﺪد اﻟﺬري‬.‫اﻷﻋﻠﻰ ﻟﻬﺎ أوﻟﻮﻳﺔ أﻋﻠﻰ‬.Br ، CI ، H ، ‫وﻫﻜﺬا أﻧﺎ‬ 5  ‫ ﻧﺘﺨﻴﻞ‬.2 ‫اﻟﺨﻄﻮة‬ ‫اﻟﺠﺰيء ﻣﻮﺟﻬً ﺎ ﺑﺤﻴﺚ‬ ‫ﻳﺘﻢ ﺗﻮﺟﻴﻪ اﻟﻤﺠﻤﻮﻋﺔ‬ ‫ذات اﻷوﻟﻮﻳﺔ اﻷﻗﻞ ﺑﻌﻴﺪً ا‬ ORGANIC CHEMISTRY lecture 10 ‫ وﻧﻼﺣﻆ ﺗﺮﺗﻴﺐ‬، ‫ﻋﻨﺎ‬ 6/7.‫اﻟﻤﺠﻤﻮﻋﺎت اﻟﻤﺘﺒﻘﻴﺔ‬ Step 2. We visualize the molecule oriented so that the group of lowest ‫إذا ﺗﺤﺮﻛﺖ ﻋﻴﻨﻨﺎ ﻓﻲ‬ ‫اﺗﺠﺎه ﻋﻘﺎرب اﻟﺴﺎﻋﺔ ﻋﻨﺪ‬ priority ‫اﻻﻧﺘﻘﺎل ﻣﻦ اﻟﻤﺠﻤﻮﻋﺔ‬ is directed away from us, and observe the arrangement of the remaining ‫ذات اﻷوﻟﻮﻳﺔ اﻟﻘﺼﻮى‬ groups. ‫إﻟﻰ اﻟﻤﺠﻤﻮﻋﺔ ذات‬ If, in proceeding from the group of highest priority to the group of second ‫اﻷوﻟﻮﻳﺔ اﻟﺜﺎﻧﻴﺔ وﻣﻦ ﺛﻢ‬ priority ‫إﻟﻰ اﻟﻤﺠﻤﻮﻋﺔ اﻟﺜﺎﻟﺜﺔ‬ and thence to the third, our eye travels in a clockwise direction, the ‫ﻓﻲ اﺗﺠﺎه ﻋﻘﺎرب‬ ‫ ﻓﺴﻴﺘﻢ ﺗﺤﺪﻳﺪ‬، ‫اﻟﺴﺎﻋﺔ‬ configuration is :‫ )ﻻﺗﻴﻨﻴﺔ‬R ‫اﻟﺘﻜﻮﻳﻦ‬ specified R (Latin : rectus, right); if counterclockwise, the configuration ‫ ﻳﻤﻴﻦ( ؛ إذا‬، ‫ﻣﺴﺘﻘﻴﻢ‬ is specified ‫ﻛﺎن ﻋﻜﺲ اﺗﺠﺎه ﻋﻘﺎرب‬ S (Latin: sinister, left). ‫ ﻳﺘﻢ ﺗﺤﺪﻳﺪ‬، ‫اﻟﺴﺎﻋﺔ‬ Thus, configurations I and II are viewed like this: :‫ )ﻻﺗﻴﻨﻲ‬S ‫اﻟﺘﻜﻮﻳﻦ‬ ، ‫ وﺑﺎﻟﺘﺎﻟﻲ‬.(‫ ﻳﺴﺎر‬، ‫ﺷﺮﻳﺮ‬ ‫ﻳُ ﻨﻈﺮ إﻟﻰ اﻟﺘﻜﻮﻳﻨﺎت‬ ‫اﻷوﻟﻰ واﻟﺜﺎﻧﻴﺔ ﻋﻠﻰ‬ :‫اﻟﻨﺤﻮ اﻟﺘﺎﻟﻲ‬ ‫ ﻳﻜﺸﻒ اﻻﺳﻢ‬.‫ ﻋﻠﻰ اﻟﺘﻮاﻟﻲ‬S ‫ و‬R ‫وﻳﺘﻢ ﺗﺤﺪﻳﺪ‬ ‫اﻟﻜﺎﻣﻞ ﻟﻠﻤﺮﻛﺐ اﻟﻨﺸﻂ ﺑﺼﺮﻳًﺎ ﻋﻤﺎ إذا ﻛﺎﻧﺖ ﻣﻌﺮوﻓﺔ‬ - (S) ، ‫ ﻋﻠﻰ ﺳﺒﻴﻞ اﻟﻤﺜﺎل‬، ‫ﺑﺘﻜﻮﻳﻦ واﺗﺠﺎه اﻟﺪوران‬ R S ‫ ﻳﻤﻜﻦ ﺗﺤﺪﻳﺪ ﺗﻌﺪﻳﻞ ﻣﺘﻘﻄﻊ‬.‫ ﻛﻠﻮرﻳﺪ ﺳﻴﺒﻮﺗﻴﻞ‬- (+) (RS) ، ‫ ﻋﻠﻰ ﺳﺒﻴﻞ اﻟﻤﺜﺎل‬، RS ‫ﺑﻮاﺳﻄﺔ اﻟﺒﺎدﺋﺔ‬.sec-butyl chloride- and are specified R and S, respectively. A complete name for an optically active compound reveals if they are known both configuration and direction of rotation, as, for example, (S)-(+)-sec- butyl chloride. A raccmic modification can be specified by the prefix RS, as, for example, (RS)-sec-butyl chloride. ‫ أﻻ‬، ‫ ﺑﺎﻟﻄﺒﻊ‬، ‫ﻳﺠﺐ ﻋﻠﻴﻨﺎ‬ We must not, of course, confuse the direction of optical rotation of a ‫ ﻧﺨﻠﻂ ﺑﻴﻦ اﺗﺠﺎه اﻟﺪوران‬compound a ‫ اﻟﺒﺼﺮي ﻟﻠﻤﺮﻛﺐ وﺑﻴﻦ‬physical property of a real substance, like melting point or boiling point ‫ ﺧﺎﺻﻴﺔ ﻣﺎدﻳﺔ ﻟﻤﺎدة‬with the ‫ ﻣﺜﻞ ﻧﻘﻄﺔ‬، ‫ﺣﻘﻴﻘﻴﺔ‬ direction in which our eve happens to travel when we imagine a molecule ‫اﻻﻧﺼﻬﺎر أو ﻧﻘﻄﺔ اﻟﻐﻠﻴﺎن‬ ‫ ﻣﻊ اﻻﺗﺠﺎه اﻟﺬي ﺗﺴﻴﺮ ﻓﻴﻪ‬held in an arbitrary manner. So far as we are concerned, unless we ‫ ﻋﺸﻴﺘﻨﺎ ﻋﻨﺪﻣﺎ ﻧﺘﺨﻴﻞ‬happen to know what has been established experimentally for a specific ً ‫ﻣﺤﺘﺠﺰا ﺑﻄﺮﻳﻘﺔ‬ ‫ﺟﺰيءا‬ ً compound, we have no idea whether (+ ) or ( - )rotation is associated \\ith ‫ ﺑﻘﺪر ﻣﺎ ﻧﺸﻌﺮ‬. ‫ ﻋﺸﻮاﺋﻴﺔ‬the (R)- or the (S)-configuration. ‫ ﻣﺎ ﻟﻢ ﻧﻌﺮف ﻣﺎ ﺗﻢ‬، ‫ﺑﺎﻟﻘﻠﻖ‬ ‫ﺗﺠﺮﻳﺒﻴﺎ ﻟﻤﺮﻛﺐ‬ ً ‫إﻧﺸﺎؤه‬ ‫ ﻓﻠﻴﺲ ﻟﺪﻳﻨﺎ أي‬، ‫ﻣﻌﻴﻦ‬ ‫( أو‬+) ‫ﻓﻜﺮة ﻋﻤﺎ إذا ﻛﺎن‬ ‫( ﻳﺮﺗﺒﻂ ﺑﺎﻟﺘﻨﺎوب \\ ﻣﻊ‬-).‫ﺗﺮﺗﻴﺐ‬- (S) ‫ أو‬- (R) 6  ORGANIC CHEMISTRY lecture 10 7/7 S R 🤍 zahraa 7