text: The exactly solvable Kitaev honeycomb lattice model is realized as the low energy eﬀect Hamil- 
  tonian of a spin-1/2 model with spin rotation and time-reversal symmetry. The mapping to low 
  energy eﬀective Hamiltonian is exact, without truncation errors in traditional perturbation series 
  expansions. This model consists of a honeycomb lattice of clusters of four spin-1/2 moments, and 
  contains short-range interactions up to six-spin(or eight-spin) terms. The spin in the Kitaev model 
  is represented not as these spin-1/2 moments, but as pseudo-spin of the two-dimensional spin singlet 
  sector of the four antiferromagnetically coupled spin-1/2 moments within each cluster. Spin corre- 
  lations in the Kitaev model are mapped to dimer correlations or spin-chirality correlations in this 
  model. This exact construction is quite general and can be used to make other interesting spin-1/2 
  models from spin rotation invariant Hamiltonians. We discuss two possible routes to generate the 
  high order spin interactions from more natural couplings, which involves perturbative expansions 
  thus breaks the exact mapping, although in a controlled manner. 