Véronique Bellosta

Regioselective ring opening of epoxides by nucleophiles mediated by lithium bistrifluoromethanesulfonimide

Abstract In the presence of LiNTf 2 , epoxides undergo ring opening with high regioselectivity and in good yield when they are treated with nucleophiles such as amines, hydrazines and thiophenol.

Formation of radicals by irradiation of alkyl halides in the presence of triethylamine

Abstract The irradiation of alkyl halides in the presence of triethylamine leads to the formation of the corresponding reduction products or to the cyclized products when an unsaturation is present.

Oxidative cleavage of 2-substituted cycloalkane-1,3-diones and of cyclic β-ketoesters by copper perchlorate / oxygen

Abstract A preparative method for the synthesis of (ω-1), ω-dioxocarboxylic acids and (ω-1)-oxoalkanedioic acids monoesters by respective oxidative cleavage of 2-substituted cycloalkane-1,3-diones and cyclic β-ketoesters, by copper perchlorate in acetonitrile in an oxygen atmosphere, is reported.

Radical anion ring opening reactions via photochemically induced electron transfer

Abstract Ketyl radical anions can induce the opening of adjacent strained ring such as cyclopropane, cyclobutane, epoxide and 7-oxabicyclo[2.2.1]heptane.

Formal total synthesis of (+)-methynolide

A formal total synthesis of (+)-methynolide was achieved in 23 steps highlighted by a crotylboration, a ring-closing metathesis, a Sharpless kinetic resolution of an allylic alcohol and a Takai reaction.

A short synthesis of the C1–C7 fragment of methymycin by ring-closing olefin metathesis

Abstract The synthesis of the C1–C7 fragment of methymycin was achieved via a ring-closing olefin metathesis employing Grubbs catalyst in the presence of Ti(O i Pr) 4 .

Mild nonepimerizing N-alkylation of amines by alcohols without transition metals.

A one-pot two-step sequence involving an oxidation/imine-iminium formation/reduction allowed the N-alkylation of amines by alcohols without any epimerization when optically active alcohols and amines are involved in the process.

A Versatile Route to the Tulearin Class of Macrolactones: Synthesis of a Stereoisomer of Tulearin A

A versatile synthetic approach to the tulearin class of macrolactones has been developed and deployed to make a stereoisomer of tulearin A. The knowledge gained about structure and synthesis will expedite the assignment of the stereostructure of this new anticancer agent.

Synthesis of the monomeric counterpart of marinomycin A.

An efficient and highly convergent synthesis of the monomeric counterpart of the antitumor-antibiotic marine natural product marinomycin A was achieved by using optically active titanium complexes to control the configuration of the stereogenic centers, a highly stereo- and regioselective cross-metathesis to generate the (E)-configured C20-C21 double bond, and a Horner-Wadsworth-Emmons olefination followed by a Pd-catalyzed Stille cross-coupling to construct the tetraene moiety.

Diastereodivergent Addition of Allenylzincs to Aryl Glyoxylates

A diastereodivergent addition of allenylzincs to aryl glyoxylates was observed depending on the method used for the preparation of the allenylzinc reagent. The allenylzincs were prepared from propargylic benzoates in the presence of a palladium catalyst or by metalation of alkynes.