Preparation and some reactions of neophyltin anions

Article abstract of DOI:10.1016/0022-328X(94)05324-5

A study on the preparation on the trineophyltin and mixed methylneophyltin anions and subsequent reactions of these anions is reported.It was found that whereas mixed hydrides MenNph3-nSnH (n=1,2) react with NaH in DMSO to give the corresponding organotin sodium anions (60-70percent yield), trineophyltin hydride reacts with NaH to give hexaneophylditin as the only product (32 percent).The reaction of tin halides MenNph3-nX (X = Cl, Br; n = 0, 1, 2) with lithium in THF yields the corresponding organotinlithium anions (70 percent).The tin anions were reacted with various alkylhalides.The 1,4 addition of trineophyltinlithium (10^<*>) to α,β-unsaturated enones followed by the reaction of the intermediate carbanions with methyl iodide, leads with benzylideneacetone to a mixture of the corresponding threo (34 percent) and erythro (25 percent) diastereoisomers.Under the same reaction conditions, the addition of 10^<*> to chalcone proceeded with complete stereoselectivity to give the diastereoisomer threo (60 percent) as the only product.Full 1H and 13C NMR data of the new organotins are given. Keywords: Tin; Stereoselective synthesis