115410-95-2

Upstream product

• 127280-51-7 (1α,4α,4aα,5β,8β,8aα)-4a,5,8,8a-Tetrahydro-11-oxo-1-phenyl-4,1-(epoxymethano)-5,8-methanophthalazin-4(1H)-carbonsaeure-methylester 
• 98171-26-7 6-Oxo-5-phenyl-6H-[1,3,4]oxadiazine-2-carboxylic acid methyl ester 
• 121-46-0 bicyclo[2.2.1]hepta-2,5-diene 
• 115410-84-9 Oxo-[3-(2-oxo-1-phenyl-vinyl)-bicyclo[2.2.1]hept-5-en-2-yl]-acetic acid methyl ester 

Relevant academic research and scientific papers

Cycloadditions of 6H-1,3,4-oxadiazin-6-ones (4,5-diaza-α-pyrones), 15. Reactions of 6H-1,3,4-oxadiazin-6-ones with norbornadiene. A new route to 3,6-disubstituted α-pyrones

Upon reaction with norbornadiene, ten disubstituted 1,3,4-oxadiazin-6-ones 1 were converted into 3,6-disubstituted α-pyrones 6. For this purpose, solutions of the substrates were treated with boron trifluoride-ether or trifluoroacetic acid. The smooth formation of 6 was also observed when a γ-oxo ketene, initially generated by heating a solution of the substrates in the absence of boron trifluoride-ether, was allowed to react with the Lewis acid. Without use of an acid, only 6f could be obtained free from further compounds, whereas in the other cases enol lactones and 1:2 products of the types 8 and 7 were formed additionally. Oxadiazinone 1j gave enol lactone 10 in the noncatalysed reaction. VCH Verlagsgesellschaft mbH, 1996.

Cycloadditions of 1,3,4-Oxadiazin-6-ones (4,5-Diaza-α-pyrones), 9. - Methyl 6-Oxo-5-phenyl-1,3,4-oxadiazin-2-carboxylate - Synthesis and Reactions with Norbornene, Norbornadiene, Cyclopropenes, Cyclobutene, and Benzvalene

Methyl 6-oxo-5-phenyl-1,3,4-oxadiazin-2-carboxylate (7) was prepared by treatment of hydrazone 6 with dicyclohexylcarbodiimide.The reactions of 7 with norbornene and norbornadiene afforded the Diels-Alder adducts 8 and 9, respectively, which decomposed in solution at 20 deg C to give mainly the γ-oxoketenes 10 and 12 and small amounts of the β-lactones 11 and 13, respectively.The stable γ-oxoketenes 10, 12, and the bis(γ-oxoketene) 14 were obtained directly from solutions of 7 and the respective olefin.Cyclopropene, 1-methylcyclopropene, and cyclobutene were converted by 7 mainly into the oxepin derivatives 15, 17, 18, and the oxocin derivative 19, respectively.Benzvalene and 7 provided the tetracyclo2,8.04,6>octanone 21.In these reactions, small quantities of β-lactones were formed, too, which together with the β-lactones 11 and 13 give evidence for the dihydropyryliumolates 24 as intermediates in the thermal denitrogenation of the Diels-Alder adducts of 7, e.g. 8 and 9.

INTRAMOLEKULARE -CYCLOADDITIONEN VON γ-OXOKETENEN

The γ-oxoketenes, which are accessible from methyl 1,3,4-oxadiazin-6-one-2-carboxylate 1 and cycloalkenes, are shown to undergo an intramolecular cycloaddition either on heating or on photolysis to give different stereoisomers of β-lactones of the 3-oxo-2-oxa-bicyclohexane-type.