Synthesis of 1,4-diaza-7-oxabicyclo[4.3.0]non-2-en-6-ones by cyclization of 1,1-bis(trimethylsiloxy)ketene acetals with pyrazine and quinoxaline

1,4-Diaza-7-oxabicyclo[4.3.0]non-2-en-6-ones were prepared by cyclization of 1,1-bis(trimethylsiloxy)ketene acetals with pyrazine and quinoxaline.