A Convenient One-Step Synthesis of 2-Hydroxy-1,3,5-Benzenetricarbaldehyde

The hexamethylenetetramine/trifluoroacetic acid system was demonstrated to be capable of introducing three aldehyde groups into the phenol molecule. Facile, one-step procedures were developed for the preparation of hitherto difficult to synthesize 2-hydroxy-1,3,5-benzenetricarbaldehyde starting from either phenol or 4-hydroxybenzaldehyde. New pKa measurements showed 2-hydroxy-1,3,5-benzenetricarbaldehyde to be an acid stronger than previously reported.     

A Convenient One-Step Synthesis of 1,1,4,4-Tetrachloro-1,3-butadiene

During the course of our studies on selective chlorination by copper (II) chlorida¹ we considared it of intarest to tast the stability of the solvent commonly amployed by us – sulfolane– ⁺⁾ towards this haloganating agent.     

A Convenient Synthesis of O-Alkyl-S-allenyl-Phosphoramidates

Ten title compounds 2a-j were synthesized by utilising mercuric (I) catalyzed thiono-thiolo rearrangement of O-propargyl-O-alkyl-pho-sphoramidothionates (1a-j) in HAc-NaAc buffer (PH=3.6). The yield of compounds 2a-e and 2f-j is 58–67% and 12–41%. This is the example of [3,3]-sigmatropic type rearrangement of 1,5-enyne system in thionop hosphoramidate chemistry.     

A Convenient Synthesis of Sendaverine

Sendaverine was isolated from Corydalis aurea willd by Manske and it was found to possess a tetrahydro-isoquinoline skeleton¹. The structural formula of the alkaloid has been established by the unambiguous synthesis by Kametani² and Miwako Mori et al.³     

A Convenient Synthesis of Tryptamines

Reaction of tosylmethyl isocyanide with substituted formyl indoles gave the nitrile with one more carbon atom. Hydrogenation of this nitrile afforded the corresponding tryptamine.     

A Convenient Synthesis of Thioimidates

Thioimidates are useful reagents in preparative organic chemistry: for example, they are key intermediates for the synthesis of β-lactams bearing a thioether function at position 4, via an “acid chlorideimine” type reaction.¹     

A Convenient Synthesis of Protoanemonin

Abstract

A new convenient synthesis of protoanemonin (1) starting from 2-deoxy-d-ribose (3) is described. A key step in the sequence is the successive β- and δ-eliminations of 3,5-di-O-p-toluoyl-2-deoxy-d-ribono-1,4-lactone (6).     

A Convenient Synthesis of Triquinacene

We have recently reported the synthesis of a derivative of triquinacene (2,3-dihydrotriquinacen-2-one (14)⁴) from Thiele's acid (1). Although this new synthetic route is simple in concept, it suffers from a large number of chemical steps. We wish to communicate an important overall simplification of this synthetic scheme which makes readily available triquinacene (22) and several of its derivatives.     

Convenient,One-Step Syntheses of 2-Fluoroveratrole And 2-Fluoroveratraldehyde

Metalated veratraldehyde and veratrole were quenched with perchloryl fluoride to provide one-step syntheses of 2-fluoroveratraldehyde and 2-fluoroveratrole, respectively. Previous syntheses of these precursors to 2-fluorodopamine and 5-fluoronorepinephrine are multi-step processess which involve introduction of fluorine at an early stage. Perchloryl fluoride is a potentially hazardous reagent, and should be used only on an appropriate (millimolar) scale with precautions.     

A Convenient One-Step Catalytic Method for Obtaining Optically Active 2-Cyclopentenyl Benzoate from Cyclopentene

(S)-2-Cyclopentenyl benzoate has been obtained in 54–67% yield and 54–59% enantiomeric excess (ee) by oxidation of cyclopentene with tert-butyl peroxybenzoate catalyzed by copper(I) oxide and (S)-proline.     

A Convenient One-Step Synthesis of 5-(α-alkanonyl) and 5-(α-Cyclanonyl)-4-Pentanolides

The thermolysis of t-butyl perpent-4-enoate in ketones leads to the formation of 5-(α-alkanonyl) and 5-(α-cyclanonyl)-4-pentanolides with fairly good yields.     

A Convenient Synthesis of Vinyl Sulfides

tert-Alkyl sulfides, with an α-(1H-benzotriazol-1-yl) group 6 and 13 , are readily prepared from N-[(aryl-thio)methyl]-1H-benzotriazoles 3 and N-( 11 ), respectively, by reaction with BuLi and then with the appropriate electrophile. The tert-alkyl sulfides 6 and 13 are smoothly converted by BF₃. OEt₂ into vinyl sulfides 5, 7 or 12 , respectively, in satisfactory yields.     

A Convenient Synthesis of Pentafluoroethyl-Substituted Aromatics

The reaction of substituted aryl bromides and iodides with potassium pentafluoropropionate and copper (I) iodide in DMF/toluene at 150[ddot]C gives good yields of the corresponding aryl pentafluoroethyl compounds.     

A Convenient Method of N-Methylphthalimide Synthesis

We suggest a convenient method to obtain N-methyiphthalimide with a high yield in the reaction of phthalic anhydride with aqueous methylamine.     

A Convenient Synthesis of t-butyl p-Aminobenzoate

A convenient one-pot synthesis of t-butyl p-aminobenzoate is described which involves treatment of p-aminobenzoic acid with thionyl chloride, followed by reaction of the resulting p-sulfinylaminobenzoyl chloride with t-butanol.