New method for generation of β-oxido carbenoid via ligand exchange reaction of sulfoxides: A versatile procedure for one-carbon homologation of carbonyl compounds
one-carbon homologation of carbonylcompounds is described. The method is based on the rearrangement of β-oxido carbenoid which is generated via the ligand exchange reaction of the sulfinyl group of α-chloro β-hydroxy sulfoxide with tert-butyllithium. Addition of the carbanion of aryl 1-chloroalkyl sulfoxides to carbonylcompounds gave the adducts in good yields. The β-oxido carbenoid rearrangement of the
A novel method for generation of carbenoid from α-chloro sulfoxides: A new and versatile procedure for one-carbon homologation of carbonyl compounds to carbonyl compounds having an α-alkyl substituent
Addition of the carbanion of 1-chloroalkyl p-tolyl sulfoxides to carbonylcompound gave the adducts, which were treated with a base followed by t-butyllithium to afford one-carbon homologated carbonylcompounds having an alkyl group at the α-position, via the β-oxido carbenoids, in moderate to good yields.
A new synthesis of α,α-disubstituted carbonyl compounds from carbonyl compounds with one-carbon homologation
作者:Tsuyoshi Satoh、Kohsuke Miyashita
DOI:10.1016/j.tetlet.2004.04.154
日期:2004.6
with carbonyl compounds to afford adducts in high to quantitative yields. The adducts were treated with t-BuMgCl or LDA to give magnesium or lithium alkoxides, which were treated with i-PrMgCl or t-BuLi to afford the enolate with one-carbon elongation through β-oxido carbenoids. The enolate intermediates were found to be able to be trapped with electrophiles to give α,α-disubstituted carbonyl compounds
1-Chloroalkyl<i>p</i>-Tolyl Sulfoxides as Acetylide Anion Equivalent: A Novel Synthesis Including Asymmetric Synthesis of Propargylic Alcohols from Carbonyl Compounds
作者:Tsuyoshi Satoh、Yasumasa Hayashi、Koji Yamakawa
DOI:10.1246/bcsj.64.2153
日期:1991.7
Addition of the carbanion of 1-chloroalkyl p-tolyl sulfoxide to carbonyl compounds gave the adducts, which were heated in refluxing toluene or xylene to give vinyl chlorides in high overall yield. Dehydrochlorination of the vinyl chlorides with excess n-BuLi afforded propargylic alcohols in high yields. Asymmetric synthesis of both enantiomers of the propargylic alcohols was realized using optically
Nucleophilic Ring-Opening of Chlorooxiranes: A New Synthesis of α-Hydroxy α′-Substituted Ketones from Carbonyl Compounds and 1-Chloroalkyl<i>p</i>-Tolyl Sulfoxides
The addition of 1-chloroalkyl p-tolyl sulfoxides to carbonyl compounds gave adducts which were then converted to chlorooxiranes in two steps with good overall yields. The treatment of the chlorooxiranes with various nucleophiles gave α-hygroxy α′-substituted ketones or α-hydroxy ketones in good yields.