Lithio‐1,3,5‐trithiane Erzeugung, Umsetzung mit Elektrophilen und Verwendung als nucleophile Acylierungsmittel

Abstract

Eingegangen a m 28. September 1973 I ,3,5-Trithian selbst sowie 2-mono-und 2,4,6-trisubstituierte Trithiane lassen sich mit n-Butyllithium in Tetrahydrofuran metallieren. Umsetzung der Lithiumderivate mit Elektrophilen fiihrt zu hoher substituierten Trithianen, die teilweise in reiner Form isoliert werden kbnnen. Die NMR-Spektren der erhaltenen Produkte bei Raumtemperatur werden beschrieben. Quecksilber(1I)-assistierte Solvolyse von alkylierten Trithianen fiihrt zu Carbonylverbindungen oder deren 0-Acetalen unter ,,Herausl6sung" des htkhstsubstituierten C-Atoms, was die Verwendung von Lithiotrithianen als nucleophile Acylierungsmittel erm6glicht. Vor-und Nachteile gegeniiber der Dithian-Methode werden diskutiert. Lithio-l,3,5-trithiPnes C-tionin Solution, Reactions with Ekcb.ophiks, a d Use in Nucleopbilk Acylatioa I ,3,5-Trithiane and 2-mono-as well as 2,4,6-trisubstituted trithianes are shown to be. metallated by n-butyllithium in THF. Reaction of the lithio derivatives thus obtained with electrophiles leads to more highly substituted trithianes which in some cases can be isolated in a pure form. The n.m.r. spectra of the products a t room temperature are described. Mercury(I1)-assisted solvolysis of alkyltrithianes ,,liberates" the most highly substituted carbon with formation of carbonyl compounds or their 0-acetals. This completes a sequence of reactions which suggests use of lithiotrithianes as reagents for nucleophilic acylation. Advantages and disadvantages of this procedure compared to the dithiane method are discussed.Im Gegensatz zu 2-Lithiodithianen, die in der organischen Synthese2) als nucleophile Acylierungsmittel3.6.7) angewendet werden, haben lithiierte ~-Trithianel.3-s.7.a) *) Sonderdruckanfragen bitte an diese Autoren in G i e h bzw. Cambridge. 1) Einige der hier ausfiihrlich beschriebenen Reaktionen sind bereits in einem Ubersichtsartikel,), in einer Kurzmitteilung4) und in einer Organic Synthesis-Vorschrifts) envlhnt worden. 2) Siehe z. B. die ubersicht zur Darstellung von Cyclopentenonen : R.

Nuclear magnetic resonance investigations of configurational non-rigidity in dinuclear platinum(IV) complexes. Part 8. Fluxional properties of complexes [(PtXMe3)2(SCH2SCH2SCHMe)](X = Cl, Br or I)

“…The arguments have been laid out previously for the unsubsti tuted cyclic ligand complexes. (6). Signals due to the six non-equivalent Pt-Me environments are seen, each with its accompanying pair of 195Pt satellites due to ,J(PtH) coupling.…”

Generation and synthetic applications of 2-lithio-1,3-dithianes

“…2-n -Pentyl-1,3-dithiane (6, R = n-C5Hn). On a 0.125 molar scale a 68% yield was obtained from hexanal: bp 85°( 0.35 mm); n30D 1.5247; ir (neat) 3.86, 6.85, 7.04, 7.85, and 8.5 µ; nmr (CCU) 6.04 (degenerate t, J ' = 6.5 Hz, 2-dithiane H). Anal. Caled for C9H18S2: C, 56.82; H, 9.54; S, 33.64.…”

“…For examples, see Table III; a detailed procedure for the reaction of 5, R = CH3, with cyclohexanone has been published.25 a Satisfactory C, H, and S analyses were obtained. 6 The product was hydrolyzed under neutral conditions (HgCl2-HgO--CH3OH), and the crude hydroxyaldehyde isolated was added to a sulfuric acid-ethanol 2,4-dinitrophenylhydrazine reagent solution. The DNP of cinnamaldehyde precipitated in 76% yield and had the melting point given in the literature, 253-254°(from acetic acid).…”

“…This paper reports on investigation of the hydrogen-donating ability of various organic compounds catalyzed by chlorotris(triphenylphosphine)rhodium(I), which has high catalytic activity in the reduction of olefins by molecular hydrogen. 6 It was found that some cyclic amines such as…”