A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Novel carbocationic rearrangements of 1-styrylpropargyl alcohols

• Christine Basmadjian,
• Fan Zhang and
• Laurent Désaubry

Beilstein J. Org. Chem. 2015, 11, 1017–1022, doi:10.3762/bjoc.11.114

• molybdenum(VI)-catalyzed etherification of allylic alcohol with a gold(I)-catalyzed intramolecular cyclization process [5][6]. During the optimization process of this synthesis, we examined several catalysts to transform allylic alcohol 1 into ether 2, including Re2O7, which is described to efficiently

• catalyze this type of transformation [7]. Unexpectedly, instead of obtaining ether 2, we observed the formation of cyclopentenone 4 in 32% yield. We noticed that this reaction only occurs when Re2O7 is heated at 45 °C for 15 minutes in MeOH prior to the addition of the substrate. As far as we know, this

• from the readily prepared acyl chloride 5 and ketone 6 [4] (Scheme 3). Results and Discussion We began our study by applying the reaction conditions developed for alcohol 1 using Re2O7 (1.5%), MeOH (8 equiv) at 45 °C in DCE (entry 1, Table 1). Gratifyingly, replacing the TMS group by a TBS group

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

Re₂O₇-catalyzed reaction of hemiacetals and aldehydes with O-, S-, and C-nucleophiles

• Wantanee Sittiwong,
• Michael W. Richardson,
• Charles E. Schiaffo,
• Thomas J. Fisher and
• Patrick H. Dussault

Beilstein J. Org. Chem. 2013, 9, 1526–1532, doi:10.3762/bjoc.9.174

• dithioacetals. Reactions of hemiacetals with nitrogen nucleophiles are unsuccessful. 1,2-Dioxolan-3-ols (peroxyhemiacetals) undergo Re(VII)-promoted etherification but not allylation. Hydroperoxyacetals (1-alkoxyhydroperoxides) undergo selective exchange of the alkoxide group in the presence of either Re2O7 or

• a Brønsted acid. Keywords: allylation; hemiacetal; O,O-acetal; O,S-thioacetal; peroxyacetal; Re2O7; S,S-acetal; Introduction The synthetically important conversions of hemiacetals to acetals, thioacetals, or homoallyl ethers are typically achieved through activation of the substrate with a strong

• electron-poor amine in the presence of allyltrimethylsilane [15]. We now describe the Re2O7-promoted reactions of peroxyhemiacetals, hemiacetals, and alkoxyhydroperoxides with O-, S- and C-nucleophiles. Results In the course of investigations into potential antischistosomal and antimalarial agents [16][17

Stereoselectivity of supported alkene metathesis catalysts: a goal and a tool to characterize active sites

• Christophe Copéret

Beilstein J. Org. Chem. 2011, 7, 13–21, doi:10.3762/bjoc.7.3

• was also obtained for Re2O7/Al2O3 [40][41], which infers similar structural features for the active sites [42]. Finally, this shows that modifying the surface adsorption properties can favour the formation of primary products by slowing down secondary processes such as isomerisation, but that

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• alkenes 170 and 173, respectively. Coupling of the Wittig reagent 172 with the aldehyde 175 produced the alkene 176. Oxidative cyclization with Re2O7/lutidine afforded the corresponding trans-substituted tetrahydrofuran 177. Alternatively, Mitsunobu inversion of the free alcohol within 177, prior to its