Question

For each of the 2 pairs of reactions, the trans-compound reacts faster than the corresponding cis-compound. Draw a conformation and transition state that explains the difference between the cis- and trans-compounds reaction rate

relative rate | aq. NaOH OH tBu tBud CH3 aq. NaOH tBu CO2CH3 | aq. NaOH COZH tBu Bu och 19 NACH COCHaq NaOH Dros D.CoM ! 20 t Bu tBy-

Answer 1

GRU to BU OH C -H7+H+ Step tuli : t t Pid " (Intermediate) it here 1st step is the rate-determining step Koline hydrolysis of ester Proceeds through the formation of an intermediate in which carbonyl group becomes tetrahedral. Cs Scanned with CamScanner

Le LU Intermediate TA of | trans-isomer is, | Co. OH As a consequence stepie crowding (1,3-diaxial interaction) is fup the increase in in eis ester but not in trans-ester Therefore the transition state leading to I the formation of cis-intermediate is relatively more destabilized. . so, trans ester react faster. CodeH3 aq. Nach M OOH BBÚ - Bu r HE OH Cool trans isomer intermediate if _ x H H re-OH P OCHE above same reason tromero alon troms react for the - then eis faster ECS Seanntheith answer is above CamScanner

TH THE eis 1.5] Transition states noy OM :0; Trang [t.sa , also explain the above CS Scanned with CamScanner