4-(Phenylsulfanyl)tricyclo[3.1.0.02,6]hexan-3-one: Synthesis, Alkylation, and Base-Induced Dimerisation

1,2,3,5-Tetrahydro-1,2,3-methenopentalene, a Valence Isomer of Isoindene: Synthesis and Diels–Alder Reactions This work was supported by the Fonds der Chemischen Industrie and by Chemetall GmbH. S.E.L. and D.D.P. thank Heriot-Watt University, Edinburgh, and the European Community for an Erasmus exchange scholarship. Dipl.-Chem. Patrick Musch assisted us in the performance of the quantum-chemical calculations.

“…[9] The Pauson±Khand reaction of 6 could be performed in yields (36±41 %) similar to those of the reaction of unsubstituted benzvalene [6] and gave rise to the regioisomeric (phenylsulfanyl)cyclopentenones 7 a (Table 1) of 7 were oxidized to the sulfones, from which the allyl bromides were prepared by employing the Appel reaction. These findings made us look for a starting material containing a functional group that could be removed in a different way than a proton in the decisive stage.…”

1,2,3,5-Tetrahydro-1,2,3-methenopentalen, ein Valenzisomer des Isoindens: Synthese und Diels-Alder-Reaktionen Diese Arbeit wurde vom Fonds der Chemischen Industrie und von der Chemetall GmbH gefördert. S.E.L. und D.D.P. danken der Heriot-Watt University, Edinburgh, und der Europäischen Union für ein Erasmus-Austauschstipendium. Herr Dipl.-Chem. Patrick Musch unterstützte uns bei der Ausführung der quantenchemischen Rechnungen.

“…Diese Befunde ließen uns nach einer Ausgangsverbindung mit einer funktionellen Gruppe suchen, die im entscheidenden Schritt anders als ein Proton entfernt werden könnte. Unsere Wahl fiel auf 3‐(Phenylsulfanyl)benzvalen 6 , das in zwei Stufen leicht aus Benzvalen zugänglich ist 9. Mit ähnlichen Ausbeuten (36–41 %) wie bei unsubstituiertem Benzvalen6 konnte mit 6 die Pauson‐Khand‐Reaktion durchgeführt werden, die die regioisomeren (Phenylsulfanyl)cyclopentenone 7 a (Tabelle 1…”

3-Methylenetricyclo[3.1.0.02,6]hexane, a Tricyclic Isomer of Toluene: Synthesis and Addition onto Tetracyanoethylene

“…[20] Independently synthesised sample of 8: [2d][5b] 1 H NMR (400 MHz, CDCl 3 /C 6 D 6 ): δ ϭ 0.40/ 0.38 (q, average of J 1,6endo , J 5,6endo , and J 6endo,6exo ϭ 3.5 Hz, 1 H, 6-H endo ), 1.02/0.71 (td, average of J 1,6exo and J 5,6exo ϭ 7.5, J 6endo,6- (10): A mixture of methyltriphenylphosphonium bromide (9.83 g, 27.5 mmol) and freshly sublimed potassium tert-butoxide (3.08 g, 27.5 mmol) in diethyl ether (550 mL) was stirred at room temperature for 30 min. The resulting solution was added dropwise to a solution of 4-(phenylsulfanyl)tricyclo[3.1.0.0 2,6 ]hexan-3-one [22] (9, 5.56 g, 27.5 mmol) in diethyl ether (440 mL). Stirring was continued for 3 h at room temperature.…”

“…[21] On the other hand, a simple synthesis of its 4-phenylsulfanyl derivative 9, in three steps from benzvalene in an overall yield of 23 %, has recently been discovered. [22] This ketone could be converted into the target 7 in two steps (Scheme 2). Through a Wittig reaction, we obtained a 56% yield of the phenylsulfanyl derivative 10 of 7, and this was desulfurised by sodium in liquid ammonia.…”