29769-75-3
3-hydroxy-4-methylcyclobut-3-ene-1,2-dione
→
~67%
75966-10-8
3-chloro-4-methylcyclobut-3-ene-1,2-dione
69009-09-2
3,4,4-Triaethoxy-2-methyl-2-cyclobutenon