Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• -thiadiazine derivatives 157 in a stereoselective fashion (Scheme 41). The title compounds were screened for antiproliferative activity against the prostate cancer cell line 22Rv1, which unfortunately showed low values. Spirotrioxane steroids The synthesis of spiro-1,2,4-trioxanes was described by Singh et al

• . through the photooxygenation of allylic alcohols 158 to produce the β-hydroxyhydroperoxides 159 [66]. The latter were reacted in situ with 3-ketosteroids 160a,b in acidic medium to achieve trioxanes 161a,b in moderate to good yields, but as an inseparable mixture of diastereomers (Scheme 42). The

• bioassays against multi-drug resistant parasite Plasmodium yoelii in Swiss mice revealed that pregnane-based trioxanes 161b were the most active compounds, showing 100% suppression of parasitemia on day 4 at 48 mg/kg × 4 days, a similar activity to that of β-arteether used as positive control. Bis

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• )2-mediated formation of 1,2,4-trioxanes. Endocyclic enol ether derivative formation through Hg(II) salts. Synthesis of optically active cyclic alanine derivatives. Hg(II)-salt-mediated formation of tetrahydropyrimidin-4(1H)-one derivatives. Cyclization of ether derivatives to form stereoselective

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

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

• .10.6 Abstract The present review describes the current status of synthetic five and six-membered cyclic peroxides such as 1,2-dioxolanes, 1,2,4-trioxolanes (ozonides), 1,2-dioxanes, 1,2-dioxenes, 1,2,4-trioxanes, and 1,2,4,5-tetraoxanes. The literature from 2000 onwards is surveyed to provide an update

• , and antitumor agents. Keywords: cyclic peroxides; 1,2-dioxanes; 1,2-dioxenes; 1,2-dioxolanes; ozonides; 1,2,4,5-tetraoxanes; 1,2,4-trioxanes; 1,2,4-trioxolanes; Introduction Approaches to the synthesis of five and six-membered cyclic peroxides, such as 1,2-dioxolanes I, 1,2,4-trioxolanes (ozonides

• ) II, 1,2-dioxanes III, 1,2-dioxenes IV, 1,2,4-trioxanes V, and 1,2,4,5-tetraoxanes VI, published from 2000 to present are reviewed. These compounds are widely used in synthetic and medicinal chemistry (Figure 1). In the last decade, two reviews on this rapidly progressing field were published by

Triple-channel microreactor for biphasic gas–liquid reactions: Photosensitized oxygenations

• Ram Awatar Maurya,
• Chan Pil Park and
• Dong-Pyo Kim

Beilstein J. Org. Chem. 2011, 7, 1158–1163, doi:10.3762/bjoc.7.134

• efficiency of the triple-channel microreactor. The product of this reaction is an allyl hydroperoxide alcohol that is used in the synthesis of artemisinin-derived antimalarial 1,2,4-trioxanes [48]. The reaction in the triple-channel and in batch was carried out as aforementioned with methylene blue as

Synthesis of spiroannulated and 3-arylated 1,2,4-trioxanes from mesitylol and methyl 4-hydroxytiglate by photooxygenation and peroxyacetalization

• Axel G. Griesbeck,
• Lars-Oliver Höinck and
• Jörg M. Neudörfl

Beilstein J. Org. Chem. 2010, 6, No. 61, doi:10.3762/bjoc.6.61

• -hydroperoxy homoallylic alcohols (prepared by the ene reaction of the allylic alcohols mesitylol and methyl 4-hydroxytiglate, respectively, with singlet oxygen) to give spiroannulated 1,2,4-trioxanes 5a–5e and 9a–9e, respectively. A second series of 3-arylated trioxanes 10a–10h, that are available from the

• hydroperoxy alcohol 4 and benzaldehyde derivatives, was investigated by X-ray crystallography. Keywords: ene reaction; peracetalization; peroxides; singlet oxygen; trioxanes; Introduction The antimalaria-active molecule artemisinin (1) is a naturally occurring sesquiterpene peroxide with remarkable

• singlet oxygen ene reaction of allylic alcohols as a route to ß-hydroperoxy alcohols that can be transformed into 1,2,4-trioxanes by reaction with carbonyl compounds in the presence of Lewis acids [11]. This approach leads to simple cyclic peroxides (e.g. 2) which in some cases show similar antimalarial