A simple, versatile preparation of highly substituted 2,5-dihydro-oxoles
Abstract
3,3-dialkyl-1-lithio-1-(phenylthio)allenes (1) add efficiently to ketones only on warming to –20 °C or above; the adducts are readily cyclised by acid, or several other electrophiles, to produce highly substituted 2,5-dihydro-oxoles.