Reaction of α-Pinene Oxide with Zinc Bromide and Rearrangement of 2,2,3-Trimethyl-3-cyclopentene Products Derived Therefrom¹

Synthesis and Catalytic Properties in Olefin Epoxidation of Octahedral Dichloridodioxidomolybdenum(VI) Complexes Bearing N,N‐Dialkylamide Ligands: Crystal Structure of [Mo2O4(μ2‐O)Cl2(dmf)4]

“…The reaction of α-pinene was much slower and gave mainly campholenic aldehyde (until 28 % conversion), an important intermediate used in the fragrance industry for the synthesis of santalol, which is the principle component of sandalwood oil. [28,29] The amount of α-pinene oxide detected was residual (Ͻ1 % yield), possibly because it undergoes Lewis acid catalysed isomerisation to give campholenic aldehyde (13 % yield after 6 h). [28,29] Norbornene was reactive with tbhp in the absence of a catalyst, giving epoxynorbornane as the only product.…”

“…[28,29] The amount of α-pinene oxide detected was residual (Ͻ1 % yield), possibly because it undergoes Lewis acid catalysed isomerisation to give campholenic aldehyde (13 % yield after 6 h). [28,29] Norbornene was reactive with tbhp in the absence of a catalyst, giving epoxynorbornane as the only product. Although the initial reaction rate was relatively slow, 63 % conversion was achieved after 24 h. In the presence of 5, the TOF was much higher (321 mol mol Mo -1 h -1 ) than without catalyst, and selectivity to epoxynorbornane was 96 % at 62 % conversion, decreasing to 81 % at 100 % conversion.…”

Zeolites as Catalysts for the Synthesis of Fine Chemicals

“…However, there are numerous drawbacks associated to the use of Zn halides as catalysts, such as the fast deactivation of the catalysts, requirement for a high catalyst/substrate ratio due to their low reaction rates, the turnover numbers lower than 20 [124], and finally the need for aqueous extraction of the catalyst producing a large amount of wastes contaminated with heavy metal. Among others solid acid catalysts, zeolites appear as a good alternative to overcome some of these drawbacks.…”

The Chromyl Chloride Oxidation of α-Pinene

“…Finally, the products which result from oxidative attack on the double bond were found to be pinocamphone (2), pinocarveol (12), campholenaldehyde (13), and pinol (14). All of these are the products from initial attack on the C-2 position of a-pinene followed by rearrangements.…”

“…Acid-catalyzed opening of the epoxide also readily leads to pinocarveol (12) (13). The treatments of a-pinene oxide with zinc bromide (14) or p-toluenesulfonic acid (15) are both known to give campholenaldehyde (13) along with other products including p-cymene (7).…”