作者:John D. Roberts、Frederick O. Johnson、Rudolph A. Carboni
DOI:10.1021/ja01651a027
日期:1954.11
The endo-cis and trans-5,6-dichloronorbornenes were prepared by the respective additions of cis- and trans-dichlorocthylene to cyclopentadiene. The sterochemical assigments were confirmed by dipole moment studies. The cis-dichloride was inert to hydrolysis while the trans isomer was hydrolyzed to 3,5-dihydroxynortricyclene. Hydrogenation of the dichloride isomers gave the endo-cis- and trans-2,3-dichloronorbornanes
内顺式和反式 5,6-二氯降冰片烯是通过将顺式和反式二氯乙烯分别加入环戊二烯来制备的。通过偶极矩研究证实了立体化学分配。顺式二氯化物对水解呈惰性,而反式异构体水解为 3,5-二羟基降三环烯。二氯化物异构体的氢化得到内-顺-和反-2,3-二氯降冰片烷。与基于卤化氢优先反式消除的预期相反,饱和的顺式二氯化物似乎比反式异构体更不容易脱卤化氢,尽管在两种情况下反应都很慢。两种异构体产生相同的脱卤化氢产物,2-氯降冰片烯,其结构通过氧化为顺式-环戊烷-1,3-二羧酸和水解为降樟脑而得到证实。降冰片烯在 - 75o 下氯化得到降三环基氯和 syn-7-exo-2-dichloronorbornane。由于化合物对脱卤化氢试剂的相对惰性,后者的结构被指定(优先于外-顺-2,3-二氯降冰片烷)。内-顺-2,3-二氯降冰片烷不容易水解,但反式-2,3-二氯降冰片烷和syn-7-exo-2-二氯降冰片烷分别水