36881-01-3

Upstream product

• 304898-53-1 tert-butyl-dimethyl-[4-(2-methyl-[1,3]dioxolan-2-yl)-phenoxy]-silane 
• 107-21-1 ethylene glycol 
• 99-93-4 4-Hydroxyacetophenone 
• 64101-67-3 4-acetylphenyl p-toluenesulfonate 
• 1296794-27-8 4-(2-methyl-1,3-dioxolan-2-yl)phenyl 4-methylbenzenesulfonate 
• 149683-53-4 4-(tert-butyldimethylsilyloxy)acetophenone 

Downstream Products

• 574742-51-1 4-(2-methyl-[1,3]dioxolan-2-yl)-[1,2]benzoquinone 
• 19013-07-1 desmethoxyencecalin 
• 155853-30-8 3-methyl-1-<(2-methoxymethylenoxy)-5-(2-methyl-(1,3)dioxan-2-yl)phenyl>-2-butenol 
• 155853-29-5 2-methyl-2-(4-methoxymethylenoxyphenyl)-(1,3)dioxolane 

Relevant academic research and scientific papers

Mesoporous sulfated zirconia mediated acetalization reactions

A novel, convenient, one step synthetic procedure for the synthesis of mesoporous sulfated zirconia (m-SZ) using zirconium carbonate complex and its use as solid acid catalyst for the acetalization of different carbonyl compound is reported. The high specific BET surface area (234 m2 g -1) of m-SZ is achieved after the removal of the surfactant (cetyltrymethylammonium bromide, CTAB) through calcination at 550 °C for 6 h. Microscopic analysis indicated the presence of spherical particles with worm like pores. DRIFT (diffuse reflectance FTIR) of pyridine adsorbed m-SZ and NH3-TPD (temperature programmed desorption) analysis suggested the presence of appreciable amount of Bro?nsted acid sites. The synthesized m-SZ showed high catalytic activity towards protection of carbonyl compounds through acetal/ketal formation. For the open ketal (from cyclohexanone and methanol) 97% conversion with 100% selectivity was obtained in 1 h at room temperature under solvent free condition. The catalyst can be easily recycled after separation from the reaction system without considerable loss in catalytic activity.

First total synthesis of the only known 2-isopropyliden-2: H -benzofuran-3-one isolated from V. luetzelburgii

The first total synthesis of 5-(1-hydroxy-1-ethyl)-2-isopropyliden-2H-benzofuran-3-one, is reported in its racemic and in one of its optically active [(S)-(-)] forms. This heterocycle, isolated from Verbesina luetzelburgii, is the only known 2-isopropyliden-2H-benzofuran-3-one produced by species of Verbesina. The sequence took place in eight steps and 19% overall yield (up to 33% for the chiral form), from 4′-hydroxyacetophenone. It entailed carbonyl group protection as the 1,3-dioxolane and a phenol ortho formylation, followed by a Williamson etherification with chloroacetone and an organocatalytic cross-aldolization, to afford a 2-acetyl-2,3-dihydrobenzofuran-3-ol intermediate. The latter underwent a methyl Grignard addition to the carbonyl moiety, followed by selective oxidation of the benzylic alcohol and deprotection, resulting in a β-hydroxy diketone derivative. A MsCl-assisted dehydration of the tertiary alcohol, established the isopropylidene motif, whereas the syntheses culminated by chemical or enzymatic (carrot, celeriac) selective reductions of the exocyclic carbonyl group.

Photocatalytic Oxidation of Lignin Model Systems by Merging Visible-Light Photoredox and Palladium Catalysis

Lignin valorization has long been recognized as a sustainable solution for the renewable production of aromatic compounds. Two-step oxidation/reduction strategies, whereby the first oxidation step is required to "activate" lignin systems for controlled fragmentation reactions, have recently emerged as viable routes toward this goal. Herein we describe a catalytic protocol for oxidation of lignin model systems by combining photoredox and Pd catalysis. The developed dual catalytic protocol allowed the efficient oxidation of lignin model substrates at room temperature to afford the oxidized products in good to excellent yields.

Ti(O-i-Pr)4/Me3SiCl/Mg-mediated reductive cleavage of sulfonamides and sulfonates to amines and alcohols

A low-valent titanium generated in situ from Ti(O-i-Pr)4, Me3SiCl, and Mg powder in THF reacted with aryl- and alkyl-sulfonamides of aryl and alkyl amines in a reductive N-S/S-O/S-C bond cleaving pathway to provide the corresponding amines and hydrocarbons (and thiols) derived from the sulfonyl moiety. The reagent could also cleave sulfonates to the corresponding alcohols.

A convenient method for converting hydroxyacetophenones into their ethylene or trimethylene acetals

Various types of hydroxyacetophenones are efficiently converted into the corresponding ethylene acetals in the presence of ethane-1,2-diol, triisopropyl orthoformate, and a catalytic amount of cerium(III) trifluoromethanesulfonate under mild reaction conditions. The homologous trimethylene acetals can be also prepared in the same way. Georg Thieme Verlag Stuttgart.

Total synthesis of (±)-Aiphanol, a novel cyclooxygenase-inhibitory stilbenolignan

(±)-Aiphanol has been stereoselectively synthesized through IBX-mediated o-quinone formation, and through [4+2] cycloaddition of the o-quinone and cinnamyl alcohol unit.