TANDEM CARBENE INSERTION SEMIPINACOL REARRANGEMENT OF 1-ALKYNYLCYCLOBUTENOLS - A FACILE SYNTHESIS OF 2-ALKENYL-4-CYCLOPENTENE-1,3-DIONES

1994-02-25
Zora, Metin
HERNDON, JAMES W
Reaction of chromium carbene complexes and 1-alkynylcyclobutenols leads to 2-alkenyl-4-cyclopentene-1,3-diones. Initial allkyne insertion affords a highly electrophilic carbene complex, which then undergoes an alkyl shift-ring expansion, ultimately producing 2-alkenyl-4-cyclopentene-1,3-diones.