Synthesis of an Isotopically Isomeric Mixture of 1,4,6,8-Tetramethyl[13C2]azulene and Its Thermal Reaction with Dimethyl Acetylenedicarboxylate
作者:Reza-Ali Fallahpour、Hans-J�rgen Hansen
DOI:10.1002/hlca.19950780604
日期:1995.9.20
8-tetramethyl[1,3-13C2]-, -[1,3a-13C2]-, -[2,3a-13C2]-, -[2,8a-13C2]-, and -[3,8a-13C2]azulene (5; cf. Scheme 8 and Fig. 2). The measured 2J(13C, 13C) values of [13C2]-20 and [13C2]-5 are listed in Tables 1 and 2. Thermal reaction of the 1:1:1:1:1 mixture [13C2]-5 with the four-fold amount of dimethyl acetylenedicarboxylate (ADM) at 200° in tetralin (cf. Scheme 2) gave 5,6,8,10-tetramethyl-[13C2]heptalene-1
由相应的标记的[ 13 C 2 ]环戊二烯制备四氢呋喃(THF)中的[1,3- 13 C 2 ]环戊二烯酸钠,由相应的标记物由13 CO 2和(氯甲基)三甲基硅烷合成(参见方案10),根据既定程序。它可以表明的乙酸热解顺式-环戊烷-1,2-二基二乙酸酯(顺式- 22)在550±5°下减压(60托),得到5倍的环戊二烯如反式- 22。钠[1,3- 13 C 2]环戊二烯与THF中的2,4,6-三甲基四氟硼酸吡啶鎓导致形成统计上预期的4,6,8-三甲基[1,3a- 13 C 2 ],-[2,3a] 2:2:1混合物- 13 ç 2 ] - ,以及- [1,3- 13 ç 2 ]薁(20 ;参见方案7和图1)。2:2:1混合物[ 13 C 2 ] -20的甲酰化和还原导致形成1,4,6,8-四甲基[1,3- 13 ]的1:1:1:1:1混合物C 2 ]-,-[1,3a- 13 C 2 ]-,-[2