Aldehydes Dibutyltin oxide

Keywords aromatic aldehyde, hydroxylamine hydrochloride, dibutyltin oxide, microwave irradiation, nitrile... 

There are very few examples of Lewis base-promoted allylations of aldehydes with allylstannanes. In 1992 Baba disclosed an intriguing method for allylation of aldehydes with allyl- and 2-butenyltributylstannanes in the presence of catalytic-amounts of dibutyltin dichloride and certain coactivators such as tetrabutylammo-nium iodide, tributylphosphine oxide, HMPA or tetraphenylphosphonium iodide [76]. No definitive mechanistic information is available on the role of the co-activators the authors speculate that the ligands accelerate the metathesis to form allyldibutyltin chloride which is the actual nucleophile. The same group has recently reported the use of a lead(II) iodide/HMPA catalyst for the allylation of a,yff-epoxyketones [76bj. 

The solid-phase total synthesis of (S)-zearalenone by Nicolaou et al. (372) started with the preparation of the resins 488 and 489 from the Merrifield resin (486, Scheme 9.1). Oxidation, followed by olefination of the resulting aldehyde, gave a polystyrene vinyl resin (487), which was converted into dibutyltin chloride 488. In this process, the stannylation reagent n-Bu2SnHCl was formed in situ from -Bu2SnCl2 and n-Bu2SnH2. Reduction of 488 yielded the polymer supported tin hydride 489. 

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