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2,4(3H,5if)-Furandione (/3-tetronic acid, 1) undergoes a base-catalyzed aldol condensation with aromatic aldehydes to afford the 1:1 condensation products 3-(arylmethylene)-2,4(3if,5H)-furandiones 2. The 1:1 condensation products 2 are also obtained when the reaction is acid catalyzed, and this constitutes a more convenient synthesis of 2. The furandiones 2 are formed as a mixture of two geometric isomers, whose structures have been tentatively assigned on the basis of *H NMR data. Preliminary investigations dealing with condensations of 1 with aliphatic aldehydes reveal that, under all conditions employed, the products contain 2 equiv of 1 and 1 equiv of the aldehyde.Also explored are the cycloaddition reactions of 2 with triethyl phosphite, which lead to the novel furo[3,4-d]-l,2oxaphospholene ring system.

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1 20. ABSTRACT (continued) was proposed that propellant grains be made stronger through the addition of small percentages of high strength-to-weight-ratio materials; e.g., graphite fibers It was anticipated that these reinforcing elements would assume the stress* and because of their extremely large elastic moduli would tend to Imxt the strain experienced by the propellant material. This in turn would tend to limit the damage, in particular the fracturing experienced by the propellant grains, and thus limit the gas generation rate. Representative fibers and propellants were selected, mixed, and tested for sensitiveness and mechanical properties. Response to standard sensitiveness tests was relatively unaffected by fiber addition; mechanical properties of a Low Vulnerability Ammunition (LOVA) propellant, CAB/RDX, were enhanced while those of a standard propellant, M-30, were degraded.