Stereoselective synthesis of MGI-2 rotaxanes 11 using an interlocking auxiliary approach. Coupling of azide (S)-6 with o-Me acetylene half-axle (S)-7 in the presence of macrocycle 1 gave rotaxane (S,S,Rmp)-8 (Scheme 2), in which the macrocycle preferentially encircles the less hindered triazole unit, in excellent stereoselectivity (94% de). Subsequent Suzuki coupling produced rotaxane (S,S,Rmp)-9 as the major co-conformational isomer. Transesterification with MeOH gave rotaxane (Em,Sco-c)-10, which contains an MGI-2 and a co-conformational stereogenic unit, in excellent stereopurity (92% de). Removal of the Boc group provided rotaxane (Em)-11 that only expresses MGI-2 stereochemistry, again in high stereopurity (94% de). The same synthesis starting from (R)-6 and (S)-7 gave (Zm,Sco-c)-10 (94% de) which was converted to (Zm)-11 (92% de). We note that the absolute MGI-2 configuration of the product of this interlocking auxiliary approach depends not on the enantiomer of chiral auxiliary 6 used but instead on the diastereomer of the axle produced in the first coupling step; the reaction of the (S)-6/(S)-7 (Scheme 1) or (R)-6/(R)-7 pairs to give (S,S,Rmp)-8 or (R,R,Smp)-8 respectively, would both ultimately produce (Em)-11. However, unlike in the case of the direct AT-CuAAC synthesis discussed previously, a racemic mixture of starting materials would always lead to an equal mixture of MGI isomers using this approach.