Diastereoselective Thia-Claisen Rearrangement of Pyrrolidinone-Derived
Ketene N,S-Acetals

The reactive conformations in Scheme 8 depicted the wrong absolute configuration of the substrates. The correct Scheme is shown below, with conformation I now giving rise to 17a and 17b, and conformation II leading to 18a and 18b.

Scheme 8  Proposed reactive conformations of 16a (R = H) and 16b (R = Br)

The paragraph which begins ”In the case of brominated intermediate 16b" should be replaced with the following text:
”In the case of non-brominated intermediate 16a, conformation I is slightly favored over II (possibly due to the additional A^¹,³-strain in the latter conformation) and the major product is 17a. For the brominated analogue 16b, it appears that conformation II is strongly favored. The reasons for this unexpected reversal in selectivity are currently the subject of further investigation."

The authors thank Professor Donald Craig, Imperial College, for drawing their attention to this error.