五环[5.4.0.02,6.03,10.05,9]十一烷-8,11-二酮的还原及试剂的循环利用

Reduction of Pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione and Reagent Recycling

以环戊二烯和对苯醌为原料,经过Diels-Alder加成反应、[2+2]光照关环反应、黄鸣龙还原反应合成五环[5.4.0.0^2,6.0^3,10.0^5,9]十一烷(PCUD)。还原过程中以甲苯和一缩二乙二醇为混合溶剂,采用一锅法在单因素实验基础上考察了黄鸣龙还原过程中两不同温度、时间阶段〔(θ1、t1)和(θ2、t2)〕的反应过程对笼烃产物产率的影响。结果表明,在n(五环[5.4.0.0^2,6.0^3,10.0^5,9]十一烷-8,11-二酮)∶n(KOH)∶n(水合肼)=1∶7.5∶14,第一阶段θ1=120℃,t1=2.5 h;第二阶段θ2=180℃,t2=4 h的条件下,PCUD收率提高到76.2%。利用PCUD易挥发的特点,探索了还原过程中一缩二乙二醇和氢氧化钾的循环使用效果,在进行的11次反应及循环实验中, PCUD的平均收率达到75.2%。

The synthesis of pentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecane(PCUD) was accomplished by using cyclopentadiene and benzoquinone as raw materials through Diels-Alder addition, [2+2] cycloaddition and Huang-Minlon reduction three steps reaction. In the Huang-Minlon reduction step, using toluene and diethylene glycol as mixed reaction solvent in one-pot, the effects of reaction temperature and reaction time at two stages (θ1, t1) and (θ2, t2)on the cage hydrocarbon product yield were investigated applying an single-factor test method. When using n(pentacyclo[5.4.0.0^2,6.0^3,10.0^5,9] undecane-8,11-dione)∶n(potassium hydroxide): n(hydrazine hydrate)=1∶7.5∶14, and the reaction running at stage 1: θ1=120 ℃, t1=2.5 h, then stage 2: θ2=180 ℃, t2=4 h, the PCUD yield reached 76.2%. Subsequently, the effect of recycling diethylene glycol and potassium hydroxide was investigated in the synthesis process of Huang-Minlon reduction step and the average yield of PCUD 75.2% was obtained from a set of 11 reaction and recycles.