3.3.6.8‐Tetramethyl‐tetralon‐(1), ein Kondensationsprodukt des Acetons

Abstract

Aus den Nebenprodukten der technischen Synthese von Isophoron aus Aceton (ScholvenProzeB) konnte ein neues Kondensationsprodukt des Acetons, das 3.3.6.8-Tetramethyltetralon-(I) (I), erhalten werden. Die Konstitution von 1 wird chemisch und mit spektroskopischen Methoden aufgekllrt. 3,3,6,8-Telrunrelhyl-I-tetralone, a Condensation Product of AcetoneA new condensation product of acetone, 3,3,6,8-tetramethyl-I-tetralone (I), has been isolated from the by-products of the technical synthesis of isophorone from acetone (Scholven-process). The strucure of 1 has been determined by chemical and spectroscopic methods. Oxidation of 1 with selenium dioxide yields a diketone 10 which is remarkably reactive. The HzOz-oxidation of 10 gives the dicarboxylic acid anhydride 13, which in reaction with sulfuric acid affords the indanone carboxylic acid 15. Reduction of 13 yields the hydroxy acid 16. Hydrogenation of the diketone 10 gives the tetralindiol 17. With alkali 10 rearranges t o the hydroxyindanecarboxylic acid 18.Wahrend viele acyclische und monocyclische Kondensationsprodukte des Acetons schon lange bekannt und gut untersucht sind, liegt iiber bi-und mehrcyclische Kondensationsprodukte mit gesicherter Konstitution bisher wenig in der Literatur vor 1). Mit dem Ziel, neuartige Kondensationsprodukte des Acetons aufzufinden, haben wir die bei der technischen Synthese von Isophoron aus Aceton 2) (Scholven-ProzeR) auftretenden Nebenprodukte naher untersucht. Zwar lieBen sich aus dem hochsiedenden Substanzgemisch keine einheitlichen Verbindungen isolieren, doch konnten wir nach Iangerem Erhitzen des Materials auf 260-280" eine farblose Verbindung C14H180

The Production of Isophorone

“…Based on the published literature, the reaction network shown in Figure 3 is proposed, excluding the formation of higher condensation products such as polymers [110,124,125] or oligomers of acetone and isophorone [4,111,[126][127][128][129][130][131]. The reaction starts with acetone (1), which forms diacetone alcohol (4) through aldol reaction [5,99,132,133].…”

“…5,5-Dimethyl-3-(2-methylprop-1-en-1-yl)cyclohex-2-en-1-one (15) can further react with acetone to (E)-3-(2,4-dimethylpenta-1,3-dien-1-yl)-5,5-dimethylcyclohex-2-en-1-one (20), which is also formed through the condensation of mesityl oxide (3) with isophorone (11) [109,143]. (E)-3-(2,4-dimethylpenta-1,3-dien-1-yl)-5,5-dimethylcyclohex-2-en-1-one cyclizes to 3,3,6,8,8-pentamethyl-3,4,7,8tetrahydronaphthalen-1(2H)-one (21), which forms the insecticide 3,3,6,8-tetramethyl-3,4dihydronaphthalen-1(2H)-one (22) through the loss of methane [109,128,146,147].…”

“…The liquid-phase process has been known at least since 1941, with aqueous KOH or NaOH being used as catalysts [150]. However, the selectivity to isophorone is often less than 70% [8] because acetone and isophorone react to higher condensation products [5,8,107,110,124,128,151]. The vapor-phase condensation over heterogeneous solid base catalysts has been studied for over 80 years [152] and is considered to be the greener process [109], since the selectivity toward isophorone can be higher than the selectivity in the liquid-phase process and since no alkaline wastewater is produced [8,109], although the energy efficiency of the vapor phase process is lower [8].…”

“…The liquid-phase condensation, known as the Scholven process [128], is primarily catalyzed using homogenous alkaline catalysts, mainly aqueous sodium hydroxide or potassium hydroxide solutions [5,106]. For the liquid-phase condensation, the typical reaction temperature is between 205 and 250 • C [8,161] and the pressure is approx.…”