  We examine theoretically production of doubly strange hypernuclei, 16 {\Xi}-C
and 16 {\Lambda}{\Lambda}C, in doublecharge exchange 16O(K-, K+) reactions
using a distorted-wave impulse approximation. The inclusive K+ spectrum at the
incident momentum pK- = 1.8 GeV/c and scattering angle {\theta}lab = 0^{\circ}
is estimated in a one-step mechanism, K-p \to K+{\Xi}- via {\Xi}- doorways
caused by a {\Xi}-p-{\Lambda}{\Lambda} coupling. The calculated spectrum in the
{\Xi}- bound region indicates that the integrated cross sections are on the
order of 7-12 nb/sr for significant 1- excited states with 14C(0+, 2+) \otimes
s{\Lambda}p{\Lambda} configurations in 16 {\Lambda}{\Lambda}C via the doorway
states of the spin-stretched 15N(1/2-, 3/2-) \otimes s{\Xi}- in 16 {\Xi}-C due
to a high momentum transfer q{\Xi}- \approx 400 MeV/c. The {\Xi}- admixture
probabilities of these states are on the order of 5-9%. However, populations of
the 0+ ground state with 14C(0+) \otimes s2{\Lambda} and the 2+ excited state
with 14C(2+) \otimes s2 {\Lambda} are very small. The sensitivity of the
spectrum on the {\Xi}N-{\Lambda}{\Lambda} coupling strength enables us to
extract the nature of {\Xi}N-{\Lambda}{\Lambda} dynamics in nuclei, and the
nuclear (K-, K+) reaction can extend our knowledge of the S = -2 world.
