A-alkoxyorganostannane

The utility of a-alkoxyorganostannanes as precursors to a-alkoxyorganolithiums has been demonstrated by several groups.2 Primary a-alkoxyorganostannanes2d-fl have been used as hydroxymethyl anion equivalents.3 Direct hydroxymethylation of carbonyl compounds was achieved by Seebach and Meyers,4 who treated tributylstannylmethanol with two equivalents of butyllithium (BuLi) to produce the dianion of methanol. The dianion added to carbonyl compounds to give diols directly. 

Since Still introduced the use of a-alkoxyorganostannanes as precursors of a-alk-oxyorganolithium by hn-lithium exchange [335], this chemistry was exploited in a variety of applicahons including the stereocontrolled synthesis of complex natural molecules, such as Zoanthamine [336] and Aspidospermin [337] alkaloids and (+)-Taxusin [338]. 

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