Novel tricyclic tetrahydroazepinones were synthesized via an in situ Diels-Alder reaction of furan with cyclic allenamides. These reactive intermediates are the first examples of cyclic seven-membered allenamides and were prepared starting from N-(2-chloroallyl)-2-allylglycine derivatives via ring-closing metathesis followed by dehydrochlorination. The trapping of the intermediate cycloallene with furan occurred endo- and regioselectively and provided a convenient entry into new building blocks for medicinal chemistry. The diastereoselectivity of the cycloaddition was confirmed using quantum chemical computations.

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A new class of pyrazolone-fused 3-amino-1,3,4,7-tetrahydro-2H-azepin-2-ones was synthesized from azepane-based α,βunsaturated esters. The latter compounds were obtained efficiently from 2-Cbz-amino-N-(2-bromoallyl)-4-pentenamide derivatives through initial Pd-catalyzed methoxycarbonylation followed by ring-closing metathesis. These new 3- [a] Research

The regio‐ and diastereoselectivity of transformations of nine‐membered lactams with a Z double bond in the cyclic tether towards building blocks for medicinal chemistry was evaluated. To this end, 3‐aminohexahydrooxazoninones were synthesized using a standard ring‐closing metathesis (RCM) approach of easily available O,N‐bisallylated serine derivatives. The obtained Z double bond in the medium sized lactam was used as a handle to evaluate the stereoselectivity of electrophile induced transformations. It was shown that dibromination and electrophilic activation by NBS followed by attack of O‐nucleophiles proceeded in a diastereoselective manner. Cyclization of obtained bromohydrins and face‐selective epoxidation gave access to both diastereomers of the epoxidized lactams. Finally, a Heck‐reaction of a bromobenzyl moiety at the lactam N‐atom with the Z‐double bond resulted in the diastereoselective formation of bicyclic bridged nine‐membered lactams.

Seven-Membered Allenamides with Furan. -The corresponding allenamides are formed in situ and are directly trapped with furan to give the Diels-Alder products. -(SCHURGERS, B.; BRIGOU, B.; URBANCZYK-LIPKOWSKA, Z.; TOURWE, D.; BALLET, S.; DE PROFT, F.; VAN LOMMEN, G.; VERNIEST*, G.; Org. Lett. 16 (2014) 14, 3712-3715, http://dx.