烯、炔与高锰酸钾的反应

烯、炔与高锰酸钾的反应 一 、规律 规律一:与同一个碳原子相连的羟基个数越多越不稳定。一般情况下，与同一个 碳原子连接的羟基个数为一个时稳定，与同一个碳原子连接的羟基个数 为两个或两个以上时不稳定，易脱水生成羰基。 如: OH | OH, C, ? O = C, + H2O | | OH | OH, C, ? O = C, + H2O | | OH OH OH | OH, C,OH ? O = C,OH + H2O ? O= C=O + H2O | | OH OH 规律二:与羰基碳原子连接的氢原子易被氧化为羟基。即醛基易被氧化为羧基。 O O || || —C—H ? — C—OH Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 规律三:C?C键、C= C键中的π键易断裂, σ键较难断裂。所以含C?C 键、 C= C键的物质可以被高锰酸钾溶液氧化，而烷烃类不能被高锰酸 钾溶液氧化。 C?C 键、C= C键被氧化时，C?C 键、C= C的每断裂一个键， 均在两个碳原子上各氧化添加一个羟基。 若是稀的、冷的、中性或碱性的高锰酸钾溶液(即氧化性弱的高 锰酸钾溶液)，则C?C 键、C= C键中的π键断裂，而σ键仍不断 裂。即: OH OH O O | | || || —C?C— ? —C—C— ? —C—C— | | OH OH OH OH | | —C=C— ? —C—C— | | | | 若是浓的、热的 、酸性的高锰酸钾溶液(即氧化性强的高锰酸钾 溶液)，则C?C 键、C= C键中的所有键均断裂。即: OH OH O O | | || || —C?C— ? —C— OH + —C—OH ? —C + —C + 2H2O | | | | OH OH OH OH OH OH O O | | || || —C=C— ? —C—OH + —C— OH ? —C + —C + 2H2O | | | | | | Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 二、实例分析 以下R均表示烃基或氢原子。 1 、烯与冷的稀的中性的或碱性的高锰酸钾反应 R2 R3 R2 R3 | | | | R1— C = C—R4 ? R1— C—C—R4 | | OH OH 2、烯与酸性的高锰酸钾反应 酸性条件下，KMnO4将碳碳双键断开: R2 R3 R2 R3 | | | | R1— C = C—R4 ? R1— C— OH + OH — C—R4 | | OH OH 与同一个碳原子连接的两个羟基 R2 R3 脱去一个水分子 | | --------------------------------? R1— C + C—R4 + 2H2O || || O O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 当 R2为H时 H R3 H R3 | | | | R1— C = C—R4 ? R1— C— OH + OH — C—R4 | | OH OH 同一个碳原子连接的两个羟基 H R3 与 脱去一个水分子 | | --------------------------------? R1— C + C—R4 + 2H2O || || O O OH R3 与羰基碳原子连接的氢原子被氧化为羟基 | | ---------------------------------------? R1— C + C—R4 + 2H2O || || O O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 当 RI、R2均为H时 H R3 H R3 | | | | H— C = C—R4 ? H — C— OH + OH — C—R4 | | OH OH 同一个碳原子连接的两个羟基 H R3 与 脱去一个水分子 | | --------------------------------? H—C =O + C—R4 + 2H2O || O OH R3 与羰基碳原子连接的氢原子被氧化为羟基 | | --------------------------------------? OH— C + C—R4 + 2H2O || || O O 与同一个碳原子连接的两个羟基 R3 脱去一个水分子 | --------------------------------? O= C =O?+ C—R4 + 3H2O || O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 3 、炔与冷的稀的中性的或碱性的高锰酸钾反应 OH OH | | R1— C ? C—R2 ? R1— C—C—R2 | | OH OH 与同一个碳原子连接的两个羟基 O O 脱去一个水分子 || || ------------------------------------? R1— C—C—R2 + 2H2O 当 R2为H时 OH OH | | R1— C ? C—H --------------------? R1— C—C—H | | OH OH 与同一个碳原子连接的两个羟基 O O 脱去一个水分子 || || --------------------------------? R1— C—C—H + 2H2O O O 与羰基碳原子连接的氢原子被氧化为羟基 || || -------------------------------------? R1— C—C—OH + 2H2O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 当 R1、R2均为H时 OH OH | | H— C ? C—H --------------------? H— C—C—H | | OH OH 与同一个碳原子连接的两个羟基 O O 脱去一个水分子 || || ------------------------------------? H— C—C—H + 2H2O O O 与羰基碳原子连接的氢原子被氧化为羟基 || || -------------------------------------? OH—C—C—OH + 2H2O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 4、炔与酸性的高锰酸钾反应 酸性条件下，KMnO4将碳碳叁键断开: OH OH | | R1— C ? C—R2 ? R1— C— OH + OH— C—R2 | | OH OH 与同一个碳原子连接的两个羟基 O O 脱去一个水分子 || || -----------------------------------? R1— C—OH + OH —C—R2 + 2H2O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 当 R2为H时 OH OH | | R1— C ? C—H ----? H— C— OH + OH— C—H | | OH OH 与同一个碳原子连接的两个羟基 O O 脱去一个水分子 || || ----------------------------------? R1— C—OH + OH —C—H + 2H2O O O 与羰基碳原子连接的氢原子被氧化为羟基 || || ------------------------------------? R1—C—OH + OH —C—OH + 2H2O 与同一个碳原子连接的两个羟基 O 脱去一个水分子 || ------------------------------------? R1—C—OH + O = C= O + 2H2O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency 当 R1、R2均为H时 OH OH | | H— C ? C—H ----? H— C— OH + OH— C—H | | OH OH 与同一个碳原子连接的两个羟基 O O 脱去一个水分子 || || --------------------------------------? H— C—OH + OH —C—H + 2H2O O O 与羰基碳原子连接的氢原子被氧化为羟基 || || ------------------------------------? OH—C—OH + OH—C—OH + 2H2O 与同一个碳原子连接的两个羟基 脱去一个水分子 ----------------------------------? O = C = O + 4H2O Highway 1/2. Rail transportation and land use there ... Big. Urban rail transit as a low-pollution urban public transport has become a major positive development and construction of the city's main transport infrastructure through the construction of urban rail transit will help curb rapid growth in traffic demand and help reduce the core frequency