Mycosporulone synthesis

Michael Jung and colleague at UCLA have reported in Organic Letters on the synthesis of mycosporulone.

OL paper

Ring contraction to 5-membered rings

Stoltz and co-workers have reported in ACIEE on a method to make cyclopentenes with a chiral quaternary center starting from a seven membered ring precursor via a retro Aldol reaction promoted by a base.  You might be thinking:  well it’s hard to even make a seven membered ring in the first place – I guess they’re showing how good their palladium catalyzed asymmetric alkylation reaction is.

ACIEE paper

C-18 Steroids from C-19 Steroids

Wei-Shang Tian and co-workers from Shanghai Normal University have recently reported in Tetrahedron Letters on the synthesis of estrogen steroids from androgens via a retro-Aldol reaction.

TL paper