  We report on new Chandra exploratory observations of six candidate Type 2
quasars at z=0.49-0.73 selected among the most [OIII] luminous emitters from
the Sloan Digital Sky Survey (SDSS). Under the assumption that [OIII] is a
proxy for the intrinsic luminosity of the central source, their predicted
rest-frame X-ray luminosities are L(2-10keV)~10^45 erg/s. For two of the
targets, the photon statistics are good enough to allow for basic X-ray
spectral analyses, which indicate the presence of intrinsic absorption
(~10^{22-23} cm^-2) and luminous X-ray emission (L_X>10^44 erg/s). Of the
remaining four targets, two are detected with only a few (3-6) X-ray counts,
and two are undetected by Chandra. If these four sources have the large
intrinsic X-ray luminosities predicted by the [OIII] emission, then their
nuclei must be heavily obscured (N_H>few 10^23 cm^-2) and some might be Compton
thick (N_H>1.5 10^24 cm^-2). We also present the results for two Type 2 quasar
candidates serendipitously lying in the fields of the Chandra targets, and
provide an up-to-date compilation of the X-ray properties of eight additional
SDSS Type 2 quasars from archival Chandra and XMM-Newton observations (five
with moderate-quality X-ray data). The combined sample of 16 SDSS Type 2
quasars (10 X-ray detections) provides further evidence that a considerable
fraction of optically selected Type 2 quasars are obscured in the X-ray band
(at least all the objects with moderate-quality X-ray spectra), lending further
support to the findings presented in Vignali, Alexander and Comastri (2004a)
and unification schemes of Active Galactic Nuclei, and confirms the reliability
of [OIII] emission in predicting the X-ray emission in obscured quasars.
