有機化學第三章立體化學

1、同分異構(gòu)構(gòu)造異構(gòu)立體異構(gòu)碳鏈（碳架）異構(gòu)官能團位置異構(gòu)官能團異構(gòu)互變異構(gòu)構(gòu)型異構(gòu)構(gòu)象異構(gòu)順反異構(gòu)光學異構(gòu)例：庚烷碳鏈異構(gòu)體數(shù)目最長直鏈：C C C C C C C縮短一個C接到相應縮短后的碳鏈上：C C C C C CCC C C C C CC縮短二個C接到相應縮短后的碳鏈上：C C C C CC CC C C C CCCC C C C CCCC C C C CCCC C C C CCC12345678縮短三個C接到相應縮短后的碳鏈上：C C C CCC CC C C CC C CC C C CC C CC C C CCCC9同4同3同4CH3CH2CH2CH2Br1-溴丁烷CH3CH2CHC

2、H3Br2-溴丁烷CH3CHCH2BrCH32-甲基-1-溴丙烷CBrCH3CH3CH32-甲基-2-溴丙烷CH3CCH2CCH3OOCH3CCH CCH3OOHHH3CHCH3HH3CHCH3H3CCH3H3CCH3cistransHHHHHHHHHHHHCCCH3HCH3HCCHCH3CH3H順-2-丁烯反-2-丁烯CCHCH3ClC2H5CCHClCH3C2H5(Z)-2-氯-2-戊烯(E)-2-氯-2-戊烯CCHHCH3CCHCH3COOH(2E, 4Z)-3-甲基-2, 4-己二烯酸CCCH3C2H5CH3H反-3-甲基-2-戊烯(Z)-3-甲基-2-戊烯CCHOOCHCH2HCCC

3、OOHHH(2Z, 5E)-2, 5-庚二烯-1, 7-二酸chiral molecules）：）：有手性現(xiàn)象的分子有手性現(xiàn)象的分子FBrClHFBrHClFBrClH手性分子手性分子鏡像鏡像CH3CHCHCH3Cl ClCH3CHCHCH2CH3Cl ClFCBrClHFCHClBr非非手性分子手性分子鏡像鏡像FClClHFClClHFClClHClBrClBrClBrClBrClBrClBr非非手性分子手性分子對映異構(gòu)體對映異構(gòu)體CH3HOHHOHCH3CH3HOHOHHCH3CH3OHHHOHCH3IIIIIICH3HOHHHOCH3I對映關系對映關系CH3HOHHOHCH3IIICH3

4、OHHHHOCH3IIICH3HOHHOHCH3IIICH3C2H5HOHCH3CC2H5OHHCH3C2H5OHH主鏈放在垂直方向上主鏈放在垂直方向上,伸向后方伸向后方CH3CC2H5OHHCH3HOHOHHCH3CH3OHHHOHCH3IIIC3 轉(zhuǎn)180o23CH3HOHHOHCH323CH3OHHCH3HOH23CH3HOHCH3OHH23IIICH3OHHCH3HOH23I32將主鏈轉(zhuǎn)至同一方向?qū)⒅麈溵D(zhuǎn)至同一方向互為鏡像，不能重合互為鏡像，不能重合2CH3HOHHOHCH3III3CH3OHHCH3OHH23CH3HOHCH3OHH23IICH3OHHCH3HOH23IIIICH3O

5、HHCH3OHH23u手性化合物的特性手性化合物的特性旋光性（旋光度旋光性（旋光度a a、比旋光，外消旋體和內(nèi)消旋體）比旋光，外消旋體和內(nèi)消旋體）CH3C2H5HOHH3CC2H5OHHCH3C2H5HOHCH3C2H5HOH交換CH3和C2H5I 的對映體交換CH3和OHH3CC2H5OHH交換 1 次交換 2 次交換 3 次H3CC2H5OHH交換H和C2H5III 的對映體CH3C2H5HOH以C H鍵為軸旋轉(zhuǎn)60oCH3C2H5OHH以C CH3鍵為軸旋轉(zhuǎn)60oCH3C2H5HOH以C OH鍵為軸旋轉(zhuǎn)60oHH3CHOC2H5CHOCH2OHHOHCHOHOH2CHHO與與IIICHO

6、CH2OHHOH交交換換 1 1 次次H與OHCHOCH2OHHHO交交換換 2 2 次次H與 CHOOHCCH2OHHHO交交換換 3 3 次次CH2OH與 CHOCHOHOH2CHHOIII（接下頁）（接下頁）CH3HHOC2H5OHHOHCH3HHC2H5HO和和23III23交交換換 1 1 次次交交換換 2 2 次次 C2 CH3與與OHC2 CH3與與HCH3HHOC2H5OHH23IOHHH3CC2H5OHH23I 的的非非對對映映異異構(gòu)構(gòu)體體（接上頁）（接上頁）OHCH3HC2H5OHH23I交交換換 1 1 次次 C3 C2H5與與OHOHCH3HOHC2H5H23I 的的非

7、非對對映映異異構(gòu)構(gòu)體體交交換換 2 2 次次 C3 H 與與OHOHCH3HHC2H5HO23IOHCH3HHC2H5HOII23（C2、C3均均交換了偶數(shù)交換了偶數(shù)次）次） 選擇選擇優(yōu)先順序優(yōu)先順序最小的原子或基團最小的原子或基團遠離觀察者，其余遠離觀察者，其余原子或基團依優(yōu)先原子或基團依優(yōu)先順序排列順序排列(S) 2 丁醇丁醇(R) 2 丁醇丁醇CH3C2H5HOHCH3C2H5OHHCH3CHC2H5OH*有一個手性碳有一個手性碳（1） 如：如： I Br Cl S P F O N C D H（2） 如：如：-CH2CH3 -CH3 -CH2Cl -CH2F -CH2OCH3 -CH2O

8、H -CH(CH3)2 -CH2CH(CH3)2BrClIHH 最小R 型CHCH2CHCH2CCCHOCHOOCCNCNNNCCCHOCH2OHHOHCHCH2OHHOHOCO123(R)- -甘甘油油醛醛（構(gòu)構(gòu)型型？）甘甘油油醛醛CHCH2CHCH2CCCHCH2CH2CH2CH3與CHCH2CH3H與CCH3CH3CH3CCCCH3CH3CH3CH3HOHCH3OHH23IICH3OHHCH3HOH23IIIICH3OHHCH3OHH23CH3OHHCH3HOH23ICH3HOHH3COHH23CH3HOHH3COHH23CH3HOHCH3OHH23IICH3OHHCH3HOH23III

9、ICH3OHHCH3OHH23手性碳與立體異構(gòu)體數(shù)目的關系：手性碳與立體異構(gòu)體數(shù)目的關系： 若分子有若分子有 n 個手性碳，個手性碳，理論上理論上有有 2n 個立體異構(gòu)體個立體異構(gòu)體（2n / 2對對 對映體。若手性碳組成相同，數(shù)目有所減少。對映體。若手性碳組成相同，數(shù)目有所減少。H3CCHCHCH3OHOHH3CCHCHC2H5OHOH*CH3HOHC2H5OHH23CH3OHHC2H5HOH23CH3OHHC2H5OHH23(2S, 3S)-2, 3-戊二醇(2R, 3R)-2, 3-戊二醇(2S, 3R)-2, 3-戊二醇CH3HOHC2H5HOH23(2R, 3S)-2, 3-戊二醇C

10、H3OHHCH3OHHCH3OHHCH3ClHHFHClFHClHHFHClFHClHHFHClFH180oCOOHHHOHHO23HOHCOOH4COOHHHOHOH23HOHCOOH4COOHHHOHHO23OHHCOOH4COOHHOHHOH23HOHCOOH4SRrSRsSSRRl連二烯型連二烯型（含有兩個互相垂直的平面）（含有兩個互相垂直的平面）CCCHClHClCCCHClHClCCCHClHHCCCHClHHCHCOOHHHOOCCHHOOCHCOOHNO2CO2HNO2CO2HNO2CO2HNO2CO2HHHHHHO2CCHCHOHCO2HOH*COOHHOHCOOHOHHCO

11、OHOHHCOOHHOHCOOHOHHCOOHOHH(R,R)-酒石酸酒石酸(S,S)-酒石酸酒石酸(R,S)-酒石酸酒石酸COOHHOHCOOHOHHCOOHOHHCOOHHOHCOOHOHHCOOHOHH熔點：比重（20o）水中溶解度pK1pK2171-174oC171-174oC146-148oC1.76g / cm31.76g / cm31.66g / cm3139g / 100ml139g / 100ml125g / 100ml2.984.344.344.822.983.23相同相同a a 一對對映體對偏振光的作用不同，一個使偏振光向順時一對對映體對偏振光的作用不同，一個使偏振光向順

12、時針方向偏轉(zhuǎn)，另一個使偏振光向逆時針方向偏轉(zhuǎn)，針方向偏轉(zhuǎn)，另一個使偏振光向逆時針方向偏轉(zhuǎn)，兩者偏轉(zhuǎn)兩者偏轉(zhuǎn)數(shù)值相同數(shù)值相同。COOHHOHCOOHOHHCOOHOHHCOOHHOH例：例：Br2hv,CH3HBrC2H5CH3HBrC2H5+CH3CH2CH2CH350%50%外消旋體性外消旋體性(racemic mixture)CH3CHCH2CH3BrCOOHOHHCOOHOHH內(nèi)消旋體表示方法內(nèi)消旋體表示方法一個手性碳的旋光性正好一個手性碳的旋光性正好被分子內(nèi)另一構(gòu)型相反的被分子內(nèi)另一構(gòu)型相反的手性碳所抵消手性碳所抵消內(nèi)消旋體內(nèi)消旋體(meso compounds)熔點：比重（20o）水

13、中溶解度pK1pK2COOHHOHCOOHOHH171-174oC210-212oC146-148oC1.76g / cm31.70g / cm31.66g / cm3139g / 100ml21g / 100ml125g / 100ml2.984.344.244.822.963.23COOHOHHCOOHHOH mesoCOOHOHHCOOHHOHCOOHOHHCOOHOHHCH3HOHCH3OHH23CH3OHHCH3HOH23CH3OHHCH3OHH23OHHCH2OHCHOHOHCH2OHCHOCHOHHOOHHOHHCH2OHOHHHCOOHCH3OHHCOOHCH3HOOHHCH2

14、OHCHOHOHCH2OHCHOCOOHHOHCOOHOHHCOOHOHHCOOHHOHCOOHOHHCOOHOHH5050H2NCOOHNH2OH2NCOOHNH2ONNOOOPhn-BuH3CHNNOOOPhn-BuCH3HHOHOCOOHNH2HOHOCOOHNH2NOONHOONOOHNOOLouis Pasteur (18221895)COONaOHHCOONH4HOHCOONaHOHCOONH4OHH1848年，年，( ) A(+) B*(+) A(+) B*(-) A(+) B*一一對對非非對對映映體體拆拆分分(+) A(+) B*(-) A(+) B*去去除除(+)B*去去除除(+)B*(+) A(-) AH2NCOOHCH3HNH2COOHCH3HL 丙丙氨氨酸酸D 丙丙氨氨酸酸()-丙丙氨氨酸酸Ac2OAcHNCOOHCH3HNHAcCOOHCH3H+外外消消旋旋體體酰基轉(zhuǎn)移酶（取自豬腎）H2NCOOHCH3H+L 丙丙氨氨酸酸D 乙乙酰酰丙丙氨氨酸酸溶溶于于乙乙醇醇不不溶溶于于乙乙醇醇NHAcCOOHCH3H選擇性去乙?；x擇性去乙?；鵚illiam S. Knowles The Nobel Prize in Chemistry 2001 for their work on chirally catalysed hydrogen