The .zeta.(Zeta) effect of tin

cis,trans,cis-6-(Trimethylstannyl)-2-decalyl tosylate (5-OTs) was prepared in order to test whether tin can assist in the formation of a carbocation over six bonds (a zeta effect). This system has the requisite diequatorial (zigzag) arrangement of nucleofuge and electrofuge to give rise to triple hyperconjugation. Comparisons were made with the axial-equatorial trans,trans,cis isomer (6-OTs) and with the analogous equatorial and axial decalin systems lacking the tin group (7-OTs and 8-OTs). The diequatorial system 5-OTs did not show a rate acceleration in comparison with the models, and its rate was sensitive to solvent nucleophilicity. Products for both 5 and 6 were substitution with inversion and elimination. These observations indicate that tin does not assist in positive charge development over six bonds.