During the development of organic chemistry, five-and six-membered rings received the
major share of systematic synthetic attention, and justifiably so. However, many organic
substances of interest contain larger rings, and it has become important to explore and
develop new avenues of approach to appropriately functionalized medium and large rings.
Three general methods leading to the synthesis of medium rings havebeen outlined by
Hesse in his outstanding recent monograph. 1® This review will emphasize two …

Free radical-mediated ring expansion and related annulations. [Erratum to document cited
in CA119(17):180410r] … Expansions and Related Annulations (Chem. Rev. 1993, 93,
2091-2115). … Page 2109, column 1, line 8, the sentence should read: “Although
intramolecular hydrogen transfer has been successfully used for ring expansion,examples
of ring expansion precluded by 1,5-hydrogen transfer have also been reported.” …