From mono-cis 2c, reaction with 4-iodobenzyl alcohol formed both di-cis-trans ( ) and di-cis-cis (not shown) isomers to a similar extent (19% 14 and 15% of the cis-cis-isomer). The relative stereochemistry at the carbonyl center was maintained, with 14 arising from a second arylation occurring trans with respect to the directing group, hence proving the potential for the direct trans-arylation. This was further supported by preparation of the trans-epimer 15 from 2c by treatment with NaOH. Arylation now gave only trans-cis-product 16 as a diastereoisomer of 14, confirming previous assignments. Interestingly the trans-trans-diastereoisomer was not observed in this instance, presumably due to the increased strain in the required all-equatorial palladacycle, resulting in unfavourable steric interactions of the directing group with the pre-installed aryl group. Scheme 3. Diarylation studies investigating the pathways of side-product formation.