Synthesis of macrocyclic and medium-sized ring thiolactones via the ring expansion of lactams†
Abstract
A side chain insertion method for the ring expansion of lactams into macrocyclic thiolactones is reported, that can also be incorporated into Successive Ring Expansion (SuRE) sequences. The reactions are less thermodynamically favourable than the analogous lactam- and lactone-forming ring expansion processes (with this notion supported by DFT data), but nonetheless, three complementary protecting group strategies have been developed to enable this challenging transformation to be achieved.
- This article is part of the themed collections: Synthetic methodology in OBC and Supramolecular chemistry in OBC