Synthesis of α-alkylidene-γ-lactones by intramolecular addition of alkoxycarbonyl free-radicals to acetylenes
✍ Scribed by Mario D. Bachi; Eric Bosch
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- French
- Weight
- 163 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
a-Alkylidene-y-lactones are obtained by treatment of chloroformate and selenocarbonate derivatives of homopropargylic alcohols with tri-n-butylstannane.
📜 SIMILAR VOLUMES
g-Hydroxy-a,b-acetylenic esters containing three adjacent and structurally very different functional groups are very useful in the synthesis of highly functionalized organic molecules. [1, 2] This class of compound is normally prepared by treatment of an alkyl propiolate with nBuLi at À78 8C
Free radica2 addition of either methyl bromoacetate or iodoacetamide to an cl, B-unsaturated ester gave the 4-substituted ghtarate or glutarimide respectively, whereas the radical cycZisation of N-bromoacetyl crotonamide gave the &substituted succinimide.
Allylic propiolates react with tributyl-or triphenylstannane to yield a-(stannyljmethylene-y-butyrolactones. a-Methylene-y-butyrolactones are easily prepared by destannylation.