STANNYLDIENES, NEW TOOLS FOR ORGANIC SYNTHESIS. PREPARATION AND REACTIVITY.

Article abstract of DOI:10.1016/0040-4020(89)80022-5

Tributylstannyl-1,3-dienes could be considered synthetic equivalents of conjugated dienic anions.The preparation of differently substituted 2- and 3-trialkylstannyl-1,3-dienes is reported starting from propargyltrimethylsilane.The position of the stannyl moiety on the dienic skeleton can be controlled by hydrostannylation of (trimethylsilyl)propargyl alcohols or stannyl cupration of (trimetylsilyl)propargyl ketones.The so obtained stannyldienes are submitted to Diels Alder reaction and the corresponding cycloadducts functionalized through the C-Sn bond.Stannyldienes are also suitable for a regiocontrolled transfer of the dienic structure by : a) tin-lithium exchange and further reaction with aldehydes to give conjugated dienic alcohols; b)coupling with acyl chlorides in the presence of palladium catalysts to give conjugated dienic ketones; c) AlCl3 promoted reaction with acyl chlorides to give allenic ketones.