Reduction Of Lactone Research Articles

Total synthesis of 3-deoxy and 3,6-dideoxy- dl-hexoses

Synthesis of stereoisomeric 3-deoxy-hexoses 24– 27 and 3,6-dideoxy-hexoses 28– 31 is reported. Butyl ( E)-2,6-dihydroxy-hex-4-enoate ( 2) was used as the starting material for the synthesis of 3-deoxy-hexoses. For the synthesis of 3,6-dideoxy-hexoses, butyl ( E)-2-acetoxy-hex-4-enoate ( 7) was employed. The synthesis involved the following successive steps: cis or trans hydroxylation of the double bond in 2 or 7, lactonisation of the resulting aldonic acid esters followed by acetylation and chromatographical separation of γ-lactones, reduction of lactones 16– 23 to lactols with disiamylborane, and acetylation of lactols to free sugars. All compounds were obtained as pure diastereomers in racemic form.

Synthesis of l-idofuranurono-6,3-lactone and its derivatives via hexodialdodifuranoses

1,2- O-Alkylidene-β- l-idofuranurono-6,3-lactones were obtained from the corresponding 5- O-toluene- p-sulphonyl-α- d-glucofuranurono-6,3-lac tones by a sequence involving lactone reduction, benzoylation of HO-6, inversion of configuration at C-5, deacylation, and lactol oxidation. Hydrogenolysis or methanolysis of 1,2- O- benzylidene-β- l-idofuranurono-6,3-lactone gave l-idofuranurono-6,3-lactone and a mixture of its methyl glycosides, respectively.

TRANSPOSITION OF LACTONE IN SESQUITERPENE LACTONE: CHEMICAL TRANSFORMATION OF α-SANTONIN INTO SESQUITERPENE α-METHYLENE-γ-LACTONE, YOMOGIN

Abstract The chemical transformation of of α-santonin (I) into yomogin (II) was investigated. Introduction of an oxygen function at C-8 of trienone (V) was effected by tert-butyl chromate to give dione (VII), Partial reductive lactonization converted VII to XIII-XV. Phenylselenenylation of XIII gave XVI which was then syn-eliminated to give yomogin (II).

Selectivity in the free-radical reduction of lactones with trichlorosilane

Selectivity in the free-radical reduction of lactones with trichlorosilane

Reaction paths to pure 5- and 6-aminofluorescein. Pitfalls encountered in conventional synthesis procedures.

Previously unrecognized pitfalls in the published procedure for the preparation of 5- and 6-isothiocyanatofluoresceins were examined. Hydrolysis of 5-nitrofluorescein diacetate with hot ethanol saturated with sodium hydroxide gave varying amounts of 5,5″-azoxydifluorescein in addition to 5-nitrofluorescein. The use of methanol and sodium hydroxide was found to give pure 5- and 6-nitrofluorescein from the corresponding diacetate. Further, reduction of 5-nitrofluorescein with hydrogen and W-2 Raney nickel gave a mixture of 5-aminofluorescein and 9-(4-amino-2-carboxyphenyl)-3,6-dihydroxyxanthene. A sodium sulphide–sodium hydrosulphide reduction system reduced 5-nitrofluorescein cleanly to the amine without reductive lactone cleavage. Synthesis and characterization of 5,5″-azoxydifluorescein, 9-(4-amino-2-carboxyphenyl)-3,6-dihydroxyxanthene, and related fluorescein and xanthene derivatives are described.

Communications- Steroids and Related Natural Products. VI. Diborane Reduction of Lactones to Cyclic Hemiacetals

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCommunications- Steroids and Related Natural Products. VI. Diborane Reduction of Lactones to Cyclic HemiacetalsGeorge Pettit, T Kasturi, Brian Green, and John KnightCite this: J. Org. Chem. 1961, 26, 11, 4773–4774Publication Date (Print):November 1, 1961Publication History Published online7 March 2003Published inissue 1 November 1961https://doi.org/10.1021/jo01069a600RIGHTS & PERMISSIONSArticle Views113Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (252 KB) Get e-Alerts Get e-Alerts

Communications- Steroids and Related Natural Products. IV. Reduction of Lactones to Cyclic Ethers.

Communications- Steroids and Related Natural Products. IV. Reduction of Lactones to Cyclic Ethers.

Reduction of Lactones to Hydroxyaldehydes with Lithium Aluminum Hydride - Correction

Reduction of Lactones to Hydroxyaldehydes with Lithium Aluminum Hydride - Correction

Reduction of Lactones to Hydroxyaldehydes with Lithium Aluminum Hydride

Reduction of Lactones to Hydroxyaldehydes with Lithium Aluminum Hydride