117500-14-8
diethyl 2-but-1-ynylpropanedioate
+
32364-41-3
1-ethenylcyclopropan-1-ol,4-methylbenzenesulfonic acid
→
~81%
158390-74-0
diethyl 2-but-1-ynyl-2-(2-cyclopropylideneethyl)propanedioate