Selective Transformations of Carbonyl Functions in the Presence of α,β-Unsaturated Ketones: Concise Asymmetric Total Synthesis of Decytospolides A and B
摘要:
Enones selectively react with a combination of PPh3 and TMSOTf to produce phosphonium silyl enol ethers, which work as protective groups of enones during the reduction of other carbonyl functions and can be easily deprotected to regenerate parent enones at workup. Furthermore, the first ketone selective alkylations in the presence of enones were also accomplished. This in situ protection method was applied to concise asymmetric total syntheses of decytospolides A and B.
Dynamic Kinetic Resolution of a Wide Range of Secondary Alcohols: Cooperation of Dicarbonylchlorido(pentabenzylcyclopentadienyl)ruthenium and CAL-B
作者:Mari Päiviö、Denys Mavrynsky、Reko Leino、Liisa T. Kanerva
DOI:10.1002/ejoc.201001703
日期:2011.3
The substrate scope in the dynamickineticresolution of secondary alcohols was studied by using 31 structurally different alcohols and isopropenyl acetate in the presence of dicarbonylchlorido(pentabenzylcyclopentadienyl)ruthenium and Candida antarctica lipase B (Novozym435, CAL-B) in toluene. The enzyme and the rutheniumcomplex were shown to function in a highly compatible manner allowing the conversion
of tertiary and secondary alcohols to give the corresponding alkanes is conventionally performed using an organosilane and a strong acid. In this study, a deoxygenation method was developed for tertiary and secondary alcohols, using trimethylsilane and trimethylsilyl iodide generated in situ from sodium borohydride and trimethylsilyl chloride, and trimethylsilyl chloride and potassium iodide, respectively
Selective Transformations of Carbonyl Functions in the Presence of α,β-Unsaturated Ketones: Concise Asymmetric Total Synthesis of Decytospolides A and B
Enones selectively react with a combination of PPh3 and TMSOTf to produce phosphonium silyl enol ethers, which work as protective groups of enones during the reduction of other carbonyl functions and can be easily deprotected to regenerate parent enones at workup. Furthermore, the first ketone selective alkylations in the presence of enones were also accomplished. This in situ protection method was applied to concise asymmetric total syntheses of decytospolides A and B.