Introduction of the methyl sulfanyl function in the ortho-position to O-carbamate functionality under standard directed metalation condition was followed by side-chain deprotonation with sec-butyl lithium at -78 °C. Upon warming to room temperature, the deprotonated species underwent intramolecular anionic rearrangement to afford N,N-diethyl-2-hydroxyarylthioacetamides. The rearranged products were cyclised with hot glacial acetic acid to afford condensed oxathiin-2-ones in excellent yields.
在标准导向
金属化条件下,将甲
硫基功能引入到O-
氨基甲酸酯的邻位后,在-78°C下用
仲丁基锂进行侧链去质子化。升温至室温后,去质子化的物种经历分子内阴离子重排,得到N,N-二乙基-2-羟基芳基
硫代乙酰胺。重排产物在热
冰醋酸中环化,以优异的产率得到稠合的氧
硫杂环己-2-酮。