Über das cis‐Glycol und das Epoxid des Benzvalens

Abstract

2963Benzvalen (1) läßt sich mit Standardmethoden in das cis-Glycol l umwandeln, das seinerseits leicht derivatisierbar ist und glatt das Ditosylat 3, das cyclische Carbonat 4 und die cyclischen Essigsäureorthoester 5 und 6 bildet. Unter Belichten nimmt l Thiophenol an der Bicyclo[t. ]hexan-3-ol (33) erhalten werden. Aufgrund der NMR-Daten der zugehörigen Methylether 34 und 35 erweist sich eine Konstitutionszuordnung in der Literatur als revisionsbedürftig. On the cis-Giycol and the Epoxide of BenzvaleneBy means of standard methods, benzvalene (1) can be transformed into the cis-glycol 2, from which derivatives such as the ditosylate 3, the cyclic carbonate 4, and the cy::lic orthoacetates 5 and 6 are readily prepared. Irradiation causes thiophenol to add across the centrat bond of the bicyclo- ]hexane-3,S-diol (11). -The epoxide 18 of benzvalene (1) may be synthesized starting either from the ortho esters 6 via the trans-chlorohydrin acetate 17 or directly from 1 with N-benzoylpercarbamidic acid, the latter reaction being the better one. lnitially, the thermolysis of 18 produces 2-oxabicyclo[3.

Cycloaddition Reactions of Dihapto-Coordinated Furans

“…Proton and carbon spectra of 15 were consistent with the proposed structure. Demonstration of this decomplexation is significant in that 2-oxabicyclo[3.2.0]hepta-3,6-dienes are readily converted to functionalized oxepins, which are of interest to both synthetic and physical chemists. , Indeed, heating 15 results in its conversion to oxepin 16 (Scheme ). There is no method presently available to form oxepins directly from furans, except under photochemical conditions, where irradiation experiments typically require longer times than those used herein and result in lower yields…”