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

• introduced to the reactor alongside cyclohexanone (65) in a single flow stream. A simple HPLC pump, mild heating (50 °C) and a residence time of 25 minutes was all that was required to give the β-hydroxy ketone 66 with >95% conversion, with modest diastereomeric ratio (dr) of 3:1 and high ee (82%). In the

Application of chiral 2-isoxazoline for the synthesis of syn-1,3-diol analogs

• Juanjuan Feng,
• Tianyu Li,
• Jiaxin Zhang and
• Peng Jiao

Beilstein J. Org. Chem. 2019, 15, 1840–1847, doi:10.3762/bjoc.15.179

• product in 95% yield, which was converted into tert-butyl (3S,5R)-6-hydroxy-3,5-O-isopropylidene-3,5-dihydroxyhexanoate in 14 steps through a β-hydroxy ketone. Keywords: β-hydroxy ketone; cycloaddition; 1,3-diol; isoxazoline; silyl nitronate; Introduction The chiral 1,3-diol structure is widespread in a

• oxidation conditions. Based on this assumption, the corresponding silyl nitronate from 3-nitropropanal or its acetal were not tried for cycloaddition. We then set to liberate the β-hydroxy ketone synthon by ring opening of the isoxazoline 3 (Scheme 3). Raney-Ni-catalyzed hydrogenolysis in the presence of

• boronic acid had been widely utilized to disconnect the N–O bond as well as to hydrolyze the resulting imine into a ketone [52]. We applied this method to deprotect the isoxazoline 3. However, the desired β-hydroxy ketone was never obtained. In one instance, the methyl ketone from a retro-aldol reaction

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• -1,3-indanodiones 77 (Scheme 26). It has been found that the intermediate 79 underwent the Stetter reaction to form the enolate intermediate 80, which next was transformed to the intermediate 81 via aldol condensation. The release of NHC gave the β-hydroxy ketone 82, which was deprotonated to enolate

Methods for the synthesis of polyhydroxylated piperidines by diastereoselective dihydroxylation: Exploitation in the two-directional synthesis of aza-C-linked disaccharide derivatives

• Andrew Kennedy,
• Adam Nelson and
• Alexis Perry

Beilstein J. Org. Chem. 2005, 1, No. 2, doi:10.1186/1860-5397-1-2

• , the stereochemical outcome of the reactions was unusual,[45] yielding the syn product 22C in low yield. In addition, the reaction was plagued by the problems with elimination – to yield the β-hydroxy ketone 23 – that we had previously encountered (see the dihydroxylation of 18, above). Unfortunately