... 2,4-DI-TERT-BUTYL- AND 2,3,4,5-TETRACHLORONORCARADIENE Mordecai B. Rubin Department of Chemistry Technion - Israel Institute of Technology Haifa 32000, Israel ... 4697 Page 2. 4698 a, R,= R2= ti b, R, = H; R; th c, R,= R2= Ct R,= t-Bu ; R2=H appearance of a new maximum