Destannylative acylation

The synthesis of different substituted finans by cyclization of 4-pentynones using potassium tert-butoxide in DMF was reported <96TL3387>. Dihydrofuran 32 can be prepared by a destannylative acylation of l-[(2-methoxyethoxy)methoxy]-2-(phenylsulfonyl)-2-(tributylstannyl)-cyclopropane. Treatment of 32 with BFj-EtjO yields 3-acyUurans via an intramolecular Prins-type reaction of the resulting oxonium ion intermediate <96TL4585>. 

The fairly well-known destannylative acylation with RCOCl is extendable to the preparation of Af-methoxy-A -methylamides using ClCON(OMe)Me as a reactant. ... 

Destannylative acylation and alkylation. A significant application of this reaction is in the preparation of ketones containing a peroxy moiety. Vinylstannanes dimerize while alkylating pronucleophiles. ... 

Destannylative acylation. Unsaturated tin compounds react with acid chlorides to give unsaturated ketones. When the tin atom is attached to a polymer, the ketone products released into solution are very easy to isolate. 

The stereospecific preparation of E- and Z-a-fluorovinylstannanes via the radical reaction of the corresponding a-fluorovinylsulfones with tributyltin hydride has been reported by McCarthy et al. These reagents undergo a variety of destannylation reactions including protolysis, deuterolysis, acylation, iodina-tion, electrophilic fluorination and the Stille coupling reaction [186-189] (Scheme 66). The last reaction has been employed successfully in the synthesis of a fluorinated thymidylate synthetase inhibitor [189] (Scheme 67). 

Another modification, involving a destannylation, gave cyclopropane 12. In this case, treatment of a but-3-en-l-yistannane with an electrophilic reagent gave initially the addition product 11 which then underwent 1,3-elimination. In a similar manner, reaction of (but-3-en-l-yl)trimethylsilane with an acyl halide gave cyclopropyl ketones 13. ... 

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