A convenient two step protocol for the synthesis of cyclopentenones and indanones,including an asymmetric variant

A one-pot palladium mediated hydrostannylation/cross-coupling protocol is used to give direct access to cross-conjugated dienones that can be utilized in Nazarov cyclizations to afford highly substituted cyclopentenones and indanones, including an asymmetric variant.     

Thiol-mediated tandem Michael-aldol reaction: a convenient method for the synthesis of fused cyclopentenones

A simple, convenient, one-pot synthetic approach towards substituted cyclopentenone derivatives via thiol-mediated tandem Michael-aldol reaction followed by acid-catalyzed thiol elimination and isomerization of 3-(2-formyl-3,4-dihydronapthalene 1-yl)-acrylic acid esters has been developed.     

Facile synthesis of 2-substituted cyclopentenones

An efficient synthesis of 2-substituted cyclopentenones is reported. Key reactions are the cylopropanation of 2,2-dimethyl-3(2H)-furanone and subsequent conversion to the title compounds by oxidative fragmentation.     

A convenient synthesis of biphenylene

An efficient one-pot reaction for the synthesis of biphenylene 1 starting from biphenyl is reported. The final product was prepared from commercially available, cheap materials in moderate yet very competitive yield. Biphenyl was ortho-lithiated to 2,2′-dilithiobiphenyl 2, which was then coupled to biphenylene.     

A convenient synthesis of geiparvarin

Acylation of 3-methyl-2,3-bis(trimethylsiloxy)-l-butene (PhLi) with (E)-2-methyl-2-butenoyl chloride gives the corresponding 3(2H)-furanone derivative, which can be readily converted to the naturally occurring antitumor agent Geiparvarin by two steps.     

Traceless solid-phase synthesis of hydroxylated cyclopentenones

Intramolecular nitrone-alkene cycloadditions on solid phase can be performed using polymer-bound hydroxylamine. Condensation of this reagent with sugar derived 4-pentenals followed by N-O cleavage, quaternization of the amine thus produced, and finally oxidative elimination of the amino group detaches the chiral hydroxylated cyclopentenones from the polymer. The natural antibiotic pentenomycin I was prepared in this way.     

A convenient synthesis of phenols

Abstract

Anilines are rapidly, often within 60?minutes, converted into the corresponding phenols in up to 87% isolated yield. The presented experimentally simple protocol display broad compatibility with a variety of functional groups, and in particular, well suited for the preparation of methyl-substituted phenols. Such phenols are not easily available by other synthetic approaches. The formation of phenolic radical coupling products was not observed even for activated anilines using this open flask method.     

A convenient synthesis of bis-dialkylaminoacetylenes

The novel compounds tris-diethylaminocyclopropenyl perchlorate, bis-diethylaminocyclopropenone, and bis-dimethylaminocyclopropenone have been made. Pyrolysis of the cyclopropenones affords bis-dimethylamino- and bis-diethylaminoacetylene, and with iron carbonyl these have been converted to iron complexes of tetrakis-dialkylaminocyclopentadienones.     

A novel synthesis of cyclopentenones and cyclohexenones via cycliacylation of lithioalkenylcarboxamides

The reaction of 1-iodo-3-bromopropene derivatives (1) with lithium enolates of N,N-dialkylcarboxamides followed by treatment of the allylation product (2) with two equiv of t-BuLi cleanly provides cyclopentenones in high yields, while the corresponding cycliacylation reaction of 6-iodo-5-hexenamides provides cyclohexenones.     

A convenient synthesis of 1-triacontanol

1 -Tricontanol, a new plant growth regulator, has been synthesised starting from stearic acid, and by two successive additions of six carbon units through enamine intermediates.     

A convenient synthesis of thiamacrocyclic dilactams

A convenient synthesis of 26‐ to 28‐membered thiamacrocyclic dilactams 8 was achieved via base‐catalyzed condensation reaction of bis‐2‐cyanoacetamides 4 with dialdehyde derivatives 7 . The reaction was assumed to be geometrically stereoselective, affording E, E′‐configuration as the only isolable isomer. N, N′‐[Alkanediylbis(thia‐2,1‐phenylene)]bis[2‐cyanoacetamides] 4 were obtained by the reaction of cyanoacetic acid with the corresponding diamine hydrochlorides 3 . © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:249–254, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20292     

A convenient synthesis of phosphonothioic acids

A method for the convenient synthesis of phosphonothioates, or phosphonothioic acids, is reported. A significant advantage of the method is the alleviation of the need for purification of intermediates, other than washing with water. No chromatography is needed and the only purification step is the crystallization of the final product. The method uses standard reagents and should be applicable to the synthesis of phosphonothioic acids bearing a range of functional groups.