Flash Vacuum Thermolysis of Terpenic Compounds in the Pínane Series

Kinetic and mechanistic aspects of myrcene production via thermal-induced β-pinene rearrangement

“…(5)) no statistically significant dependencies were observed. Product distribution for the initially formed products (2)(3)(4) found herein are in accordance with results from previous studies [9,11,22,26,42].…”

“…Under these conditions, different side-reactions occur leading to the formation of limonene (3) and c-limonene (D-1(7),8-p-menthadiene; 4), as shown in Scheme 1 [9,11,[21][22][23]. Consecutive reactions of the target compound 2 lead to the formation of further isomerization products (5, 6; Scheme 1) [11][12][13][14]23] and coke [24] resulting in a decreased selectivity for 2.…”

“…Syntheses based on pinane-type monoterpenes (e.g. 1, a-pinene) often require a thermally induced isomerization step yielding acyclic trienes (alloocimene, myrcene (2)) [7][8][9][10][11][12][13][14][15]. 2 itself is an important starting material for the commercial production of terpenic alcohols (e.g.…”

Thermal Isomerization of (+)‐cis‐ and (−)‐trans‐Pinane Leading to (−)‐β‐Citronellene and (+)‐Isocitronellene

“…Finally, a holistic approach of studying the reaction sketched in Scheme 1 in its entirety is much needed in light of the fact that differences in experimental setups, residence times, and analytical methods are most likely responsible for the oftentimes, contradicting yields, and compositions of the products reported in the literature. [4,5,13,[19][20][21] Herein, results concerning the thermal behavior of (+)-1 a and (À)-1 b and of their acyclic main products (À)-2 and (+)-3 in the gas-phase within a temperature range of 400-600 8C are presented. By using a combination of GC and NMR spectroscopic analytical techniques, the formation of side products and their structural elucidation is reported.…”

“…According to their general structure, they can be classified into three groups assigned by three reaction pathways. Two major reaction pathways (I and II) lead to the formation of b-citronellene (2) [4,5,13,[16][17][18][19][20] and isocitronellene (3) [5,20] as the main products. Whereas the formation of 2 from 1 (path I) is thoroughly investigated, the formation of 3 (path III) is mentioned in only two references.…”