Dedicated to Professor František Tureček on the occasion of his 60th birthdayLewis base catalysed enantioselective allylation of aldehydes 1 with allyltrichlorosilanes 2 (Scheme 1) has become an efficient tool for C À C bond formation, thereby providing a robust alternative to the use of allylboranes carrying stoichiometric amounts of chiral auxiliaries.[1] The resulting homoallylic alcohols 3 are popular building blocks in targetoriented synthesis. However, in contrast to the more widely known and better-developed boron analogues, the synthetic applications of allyltrichlorosilanes are currently limited to simple alkyl homologues (R 2 = alkyl). Recently, we have demonstrated that alcohols 3, resulting from the addition of g-substituted allylsilanes 2, can themselves serve as efficient allylating reagents for aldehydes 4, which has broadened the scope of the method considerably.[2] A further advancement can be achieved by attaching additional functionality to allylsilane 2, and thus to the resulting alcohol 3, that will enable further synthetic development.[3] Herein, we introduce the new bifunctional allyldisilane 6 and demonstrate its applicability in a highly stereoselective triple allylation of aldehydes, resulting in a stereocontrolled construction of trisubstituted tetrahydrofurans 8 (Scheme 2).The synthesis of allyldisilane 6 started from tetrahydropyranyl (THP)-protected propargyl alcohol 9 (Scheme 3), for which deprotonation with nBuLi, followed by alkylation with iodomethyltrimethylsilane, afforded trimethylsilyl (TMS) derivative 10 (83 %). After deprotection, the resulting alcohol was reduced with lithium aluminium hydride to give (E)-4-trimethylsilylbutenol 11 (47 % over two steps) as a pure stereoisomer. The conversion of alcohol 11 into the corresponding chloride 12 required a great deal of optimisation and the protocol employing N-chlorosuccinimide with triphenylphosphine turned out to be the most efficient, as it preserved the regio-and stereo-integrity and afforded the required allylic chloride 12 in good yield (80 %).[4] Finally, a CuCl-mediated coupling of 12 with trichlorosilane in the presence of an equimolar amount of the Hünig base [5] afforded the required allyldisilane (E)-6 (60 %) as a liquid, which can be used in situ or isolated by distillation.With the geometrically pure (E)-allyldisilane 6 in hand, we first explored a racemic variant of the allylation of aldehydes 1, employing DMF as the Lewis base activator (1-3 equiv). The reaction proceeded readily, producing ex- [a] O.