A Novel Synthetic Methods Through Alpha, Beta-Epoxy Sulfoxides and Related Compounds

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A novel methods are developed from the addition of 1-chloroalkyl aryl sulfoxides with carbonyl compounds through the chloroalcohols and alpha, beta-epoxy sulfoxides. Treatment of the alpha, beta-epoxy sulfoxides with LiClO_4 gave alpha, beta-unsaturated ketones, which were converted to allylic epoxides in three steps in good overall yields. These allylic epoxides were treated with LDA to afford spiro-linked methylenecyclopropanes in high yields. These methylenecycopropanes were then converted to fused 3-methylfurans. Thermal elimination of the chloroalcohols gave vinyl chlorides in quantitative yields, which were oxidized with ozone to afford alpha-hydroxycarboxylic acids and their derivatives in good yields. This method was developed to an asymmetric synthesis of them using optically active 1-chlorobutyl p-tolyl sulfoxide. Epoxydation of the vinyl chlorides gave chlorooxylanes, Which were reacted with various nucleophiles to afford alpha-hydroxy alpha'-substituted ketones in good yields. Treatment of the vinyl chlorides with excess n-BuLi afforded propargylic alcohols and acetylene diols in high overall yields. Swern oxidation of the above mentioned chloroalcohols gave alpha-halo alpha-alkyl beta-keto sulfoxides. These were treated with EtMgBr to give alpha-halo ketones in quite high yields.