Regio- and stereoselective selenium dioxide allylic oxidation of (E)-dialkyl alkylidenesuccinates to (Z)-allylic alcohols: synthesis of natural and unnatural butenolides.
نویسندگان
چکیده
The first SeO(2) induced (Z)-selective allylic alcohol formation of dialkyl alkylidenesuccinates has been demonstrated to accomplish one-step syntheses of several essential butenolides and fused butenolides via an unusual E- to Z- carbon-carbon double bond isomerisation followed by the lactonization pathway. The observed regio- and stereoselective SeO(2) allylic oxidation protocol has also been extended to the diastereoselective total synthesis of bioactive natural product isomintlactone, its direct conversion to mintlactone and an example of the base-catalyzed intramolecular rearrangement of γ-lactone to δ-lactone.
منابع مشابه
Regio- and stereocontrol in rhenium-catalyzed transposition of allylic alcohols.
A hydroxyl group-directed, highly regio- and stereoselective transposition of allylic alcohols based on rhenium catalysis has been developed. The method is suitable for a direct isomerization of acetals into the thermodynamically preferred isomer as long as one of the hydroxyl groups is allylic. This method will expand the scope of rhenium-catalyzed alcohol transpositions for complex molecule s...
متن کاملSynthesis of highly substituted allylic alcohols by a regio- and stereo-defined CuCl-mediated carbometallation reaction of 3-aryl-substituted secondary propargylic alcohols with Grignard reagents.
A highly regio- and stereoselective CuCl-mediated carbometallation reaction of 3-aryl-substituted secondary propargylic alcohols with alkyl, aryl, vinyl or allyl Grignard reagents for the synthesis of fully-substituted allylic alcohols was developed. The R(2) group from the Grignard reagent was successfully introduced to the 2-position of the propargylic alcohols due to the chelation of metal a...
متن کامل(Z)-Selective Enol Triflation of α-Alkoxyacetoaldehydes: Application to Synthesis of (Z)-Allylic Alcohols via Cross-Coupling Reaction and [1,2]-Wittig Rearrangement.
The stereoselective transformation of α-alkoxyacetoaldehydes to the corresponding (Z)-vinyl triflates was achieved by treatment with phenyl triflimide and DBU. The stereochemistry was explained by the "syn-effect," which was attributed primarily to an σ → π* interaction. The β-alkoxy vinyl triflates obtained were applied to the stereoselective synthesis of structurally diverse (Z)-allylic alcoh...
متن کاملA facile, rapid, one-pot regio/stereoselective synthesis of 2-iminothiazolidin-4-ones under solvent/scavenger-free conditions
A rapid and efficient one pot solvent/scavenger-free protocol for the synthesis of 2-iminothiazolidin-4-ones has been developed. Interestingly, the regio/stereoselective synthesis affords the regioisomeric (Z)-3-alkyl/aryl-2-(2-phenylcyclohex-2-enylimino)thiazolidin-4-one as the sole product in good yield. The selectivities observed have been rationalized based on the relative magnitude of the ...
متن کاملHighly selective allylborations of aldehydes using α,α-disubstituted allylic pinacol boronic esters.
α,α-Disubstituted allylic pinacol boronic esters undergo highly selective allylborations of aldehydes to give tetrasubstituted homoallylic alcohols with exceptional levels of anti-Z-selectivity (>20:1). The scope of the reaction includes both acyclic and cyclic allylic boronic esters which lead to acyclic and exocyclic tetrasubstituted homoallylic alcohols. The use of β-borylated allylic boroni...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Organic & biomolecular chemistry
دوره 9 18 شماره
صفحات -
تاریخ انتشار 2011