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The majority of cataclysmic variables are predicted to be post-period minimumsystems with degenerate donor stars, the period bouncers. Owing to theirintrinsic faintness, however, only a handful of these systems have so far beensecurely identified. We want to study the X-ray properties of two eclipsingperiod bouncers, OV Bootis and SDSS J103533.02+055158.3, that were selected forthis study due to their proximity to Earth. We have obtained XMM-Newtonphase-resolved X-ray and ultraviolet observations of the two objects forspectral and timing analysis. Owing to a recent dwarf nova outburst OV Boo wasmuch brighter than SDSS J103533.02+055158.3 at X-ray and ultravioletwavelengths and the eclipse could be studied in some detail. An updated eclipseephemeris was derived. The X-rays were shown to originate close to the whitedwarf, the boundary layer, with significant absorption affecting its spectrum.There was no absorption in SDSS J103533.02+055158.3, despite being observed atthe same inclination indicating different shapes of the disk and the disk rim.The white-dwarf temperature was re-determined for both objects: the white dwarfin OV Boo was still hot (23,000 K) five months after a dwarf nova outburst, andthe white dwarf in SDSS J103533.02+055158.3 hotter than assumed previously(Teff = 11,500 K). All three cataclysmic variables with degenerate donorsstudied so far in X-rays, including SDSS J121209.31+013627.7, were clearlydiscovered in X-rays and revealed mass accretion rates dot(M) >= 8 x 10^(-15)Msun/ yr. If their X-ray behavior is representative of the subpopulation ofperiod bouncers, the all-sky X-ray surveys with eROSITA together withcomprehensive follow-up will uncover new objects in sufficient number toaddress the remaining questions concerning late-stage cataclysmic variableevolution.

X-ray and ultraviolet observations of the eclipsing cataclysmic variables OV Bootis and SDSS J103533.02+055158.3 with degenerate donors