α-SELENOCYCLOBUTYLLITHIUM AS A 2-LITHIO-1,3-DIENE EQUIVALENT. REGIOSELECTIVE (100 percent) SYNTHESIS OF IPSENOL

Article abstract of DOI:10.1016/S0040-4039(00)93667-0

1-substituted cyclobutenes and 2-substituted dienes are prepared in high yield and regioselectively from a variety of electrophiles and cyclobutanone via α-lithio-α-seleno-cyclobutyllithium.