The analysis by Karabatsos13 emphasized the
importance that attack of the nucleophile should
occur via the least hindered pathway (Scheme 5).
Such an attack is realized in both conformations 11
(being almost identical to the Felkin-Anh conformation
9) and 12, with the latter being disfavored
because of eclipsing L with the carbonyl group rather
than M as seen in 11. Therefore, the Karabatsos
model also predicts 2 as the preferred product.