The first enantioselective synthesis of the fungal metabolite (+)-O-methylasparvenone was achieved in eight steps and 22% overall yield from inexpensive 3,4,5-trimethoxybenzaldehyde dimethyl acetal. Key steps include (i) early-stage asymmetric alkynylation of an aromatic aldehyde with a propiolate, (ii) intramolecular Friedel-Crafts acylation, and (iii) site-selective cleavage of an aryl methyl...

Due to numerous reasons, marine-obtained resources have attracted the interest of researchers. One of the subjects attracted the interest of researchers in recent years in the field of biologist marine algae due to their nutritional value, their benefits for health and their biological activities. In this study, the powder was extracted using acetone, then the extract purified by silica gel col...

Regio- and stereoselective oxidation of an unactivated C-H bond remains a central challenge in organic chemistry. Considerable effort has been devoted to identifying transition metal complexes, biological catalysts, or simplified mimics, but limited success has been achieved. Cytochrome P450 mono-oxygenases are involved in diverse types of regio- and stereoselective oxidations, and represent a ...

A de novo approach for the rapid construction of orthogonally protected l- and d-deoxysugars and analogues is described. A novel and robust silicon-acetal undergoes Prins cyclisations with a series of homoallylic alcohols in high yield and excellent stereocontrol. Modified Tamao-Fleming oxidation of the resulting silyltetrahydropyrans gives direct access to deoxyglycoside analogues and the appr...

A remarkable double [3 + 2] photocycloaddition reaction that results in the formation of fenestrane 2 from aromatic acetal 1 is reported. During the formation of 2, four carbon-carbon bonds, five new rings, and seven new stereocenters are created in a one-pot process. The reaction occurs in a sequential manner from the linear meta photocycloadduct 3, while the angular meta photocycloadduct 4 un...

In the presence of TMSOTf and a trialkylamine base, acetic acid undergoes aldol addition to non-enolizable aldehydes under exceptionally mild conditions. Acidic workup yields the beta-hydroxy carboxylic acid. The reaction appears to proceed via a three-step, one-pot process, including in situ trimethylsilyl ester formation, bis-silyl ketene acetal formation, and TMSOTf-catalyzed Mukaiyama aldol...

[reaction: see text] The beneficial influence of cis-isopropylidene acetal tether control groups, to facilitate the asymmetric synthesis of substituted decalins by intramolecular Diels-Alder reactions, is described. Compared to trans-acetonides, these cases proceed under milder conditions to afford the cis-fused adducts from an endo transition state. An unusual acetonitrile solvent effect exert...

Lamivudine is an extensively used drug in combinational therapies for treatment of AIDS and hepatitis B. Due to the presence of S, O acetal and stereogenic centres, the synthesis of lamivudine in good enantiomeric yield is a challenge for synthetic chemists. The main focus of this review article is to highlight systematically those few synthetic strategies which are reported in literature since...