barium in methanol 0.333333 h;

pyridine in acetone

4 A molecular sieve; di(n-butyl)tin oxide; triethylamine 1.) benzene, reflux, 4h; 2.) 1,2-dimethoxyethane, 2 d; Yield given. Multistep reaction. Yields of byproduct given;

1: 94 percent / pyridine 2: 80 percent / IRA 400 in OH(1-) form / methanol / 0.5 h View Scheme