J. M. Conia

Improved synthesis of β,X-unsaturated ketones by the reaction of allylic zinc bromides with nitriles.

Abstract The reaction of allylic bromides with nitriles in the presence of ZnAg couple leads, after hydrolysis, to β,X-unsaturated ketones in high yield.

Etude des petits cycles—XXXVII: Syntheses et proprietes spectrales du tetracyclopropylidene ([4]rotane) et des composes polycyclopropylspiraniques de la serie

The syntheses of [4]rotane and polycyclopropylspiranic derivatives are reported. One route involves the formation of cyclopropane rings from C4-acyloins; a second route uses the dimerisation of bicyclopropylidene. Spectroscopic data do not point to any particular electronic interactions between cyclopropane rings in these compounds.

Reaction of chloromethylcarbene with trimethylsilyl enol ethers. Synthesis of eucarvone, (±)-nuciferal and (±)-manicone.

Abstract New synthesis of Eucarvone 7 , (±)-Nuciferal 12 and (±)-Manicone 16 are described from trimethylsilyl enol ethers 2 , 10 and 14 via their chloromethylenation products by means of a two carbons homologation reaction.

Monoacetals of α-Dicarbonyl Compounds from Enol Ethers

Abstract The title compounds which are interesting synthetic intermediates are now available by several recent methods, for instance: Double α-sulfenylation of carbonyl compounds or their derivatives, followed by exchange of thioalkyl (or thioaryl) groups by alkoxy groups(1) Alkylation of lithium derivatives of the imine or hydrazone of pyruvic aldehyde dimethyl acetal(2) Reaction of acetals of α-keto-esters(3) or α-keto-amides(4) with organometallic reagents

Small ring compounds—XLI : Cyclobutene cycloadditions; synthesis and reactivity in the bicyclo[2.2.0]hexan-2-one series

Abstract Cyclobutene, prepared by base-induced elimination from tosyloxycyclobutane 19 undergoes cycloaddition with ethyl propiolate in the presence of AlCl 3 to provide ethyl bicyclo[2.2.0]hex-2-ene-2-carboxylate 20 . This cycloadduct at room temperature and in the presence of AlCl 3 undergoes forbidden ring opening into ethyl cyclohexa-1,3-diene-2-carboxylate 21 . The cycloaddition of cyclobutene with dichloroketene provides 3,3-dichlorobicyclo [2.2.0]hexan-2-one 24 and after reductive halogen removal the endo 3-chloro bicyclo[2.2.0]hexan-2-one 28 (the first study of this strained system). However, further dechlorination of 28 results in rearrangement and fragmentation reactions.

Concerning an unique intermediate in the formation of hydroperoxides and dioxetanes from monoolefins and singlet oxygen

Die isomeren Olefine (Ia) und (Ib) reagieren bei -50°C in Freon 12 mit sensibilisiertem Sauerstoff und anschliesender Reduktion mit Dimethylsulfid zu den Folgeprodukten (II)-(IV), in Abwesenheit des Reduktionsmittels erhalt man das Hydroperoxid (V) und das Dioxetan (VI).

An Improved Preparation of 3-Chloro-2-Cyclopentenone

Abstract 3-Chloro-2-enones are very versatile intermediates from which a number of 3-substituted-2-enones can be obtained (I).