Bulky peralkylated cyclopentadienes by extension of Jutzi’s pentamethylcyclopentadiene procedure
作者:Valeri Quindt、Dirk Saurenz、Oliver Schmitt、Marion Schär、Thomas Dezember、Gotthelf Wolmershäuser、Helmut Sitzmann
DOI:10.1016/s0022-328x(99)00028-5
日期:1999.5
condensation reaction with isobutyraldehyde to form trans-4,6-dimethylhept-5-en-3-one (1) and 3,5-diisopropyl-2,6-dimethyl-2,3,5,6-tetrahydro-γ-pyrone (2) upon addition of isobutyraldehyde to 1. Treatment of 2 with p-toluenesulfonic acid under mild conditions gives 2,5-dimethyl-3,4-diisopropylcyclopent-2-en-1-one (3) with concomitant loss of water. With methyl- or isopropylmagnesium chloride 3 can be converted
在碱性溶液中,戊酮3与异丁醛进行缩合反应,形成反式-4,6-二甲基庚5-烯-3-酮(1)和3,5-二异丙基-2,6-二甲基-2,3,5 ,1,4-四氢-γ-吡喃酮(2)加异丁醛至1。在温和的条件下用对甲苯磺酸处理2,得到2,5-二甲基-3,4-二异丙基环戊-2-烯-1-酮(3),同时损失了水。可以将甲基氯化镁或异丙基氯化镁3转化为相应的1,2,3,4,5-戊烷基化的环戊二烯HC 5 Me 2(CHMe 2)的互变异构混合物。3(4)或HC 5 Me 3(CHMe 2)2(5),将其与酰胺钠去质子化后,生成钠盐NaC 5 Me 2 -3,5-(CHMe 2)3 -1,2,4(6)或NaC 5 Me 3 -3,4,5-(CHMe 2)2 -1,2(7)。由6或7与MnCl 2或[FeBr 2(DME)]组成的新型茂金属[C 5 Me 3(CHMe 2)制备了2 } 2 Mn](8),[C 5