[en] Shell model calculations of the structure of ¹²C have been made using diverse potential energy sets based upon the Nijmegen one boson exchange models of the hyperon-nucleon interaction. Transition density matrix elements for excitation of low lying hypernuclear states by strangeness changing reactions upon ¹²C have been extracted and used in analyses of (K^-,π^-) and (π⁺,K⁺) cross sections. Successful fits to data have been obtained using an Analytic Distorted Wave Approximation for the scattering amplitudes. 13 refs., 1 tab., 7 figs