Butane-2,3-dione was activated towards nucleophilic addition of enecarbamates by a series of metal triflate complexes of a C2-symmetric diamine to give stereogenic, aldol-like, t-alcohols, a novel nickel(II) triflate complex was identified as a good catalyst for this asymmetric transformation, and an aquo nickel(II) complex was identified by XRD techniques.

No abstract

Erythrina alkaloids represent a rich source of complex polycyclic, bioactive natural products. In addition to their sedative and hypotensive effect, their curare-like activity and structural framework have made them attractive targets for synthetic and medicinal chemists. (+)-Dihydro-β-erythroidine (DHβE), the most potent nicotine acetylcholine receptor antagonist (nAChR) of the Erythrina family, is synthesized for the first time in 13 steps from commercially available material.

Indole 25, an advanced intermediate in a projected enantioselective total synthesis of lyngbyatoxin A 1, was prepared from allylic alcohol 11 in 9 steps and >95% ee, key transformations being the enantiospecific rearrangement of vinyl epoxide 14 and the Hemetsberger-Knittel reaction of azide 24.

Butane-2,3-dione. -(FOSSEY, J. S.; MATSUBARA, R.; VITAL, P.; KOBAYASHI*, S.; Org. Biomol. Chem. 3 (2005) 16, 2910-2913; Grad. Sch. Pharm. Sci., Univ. Tokyo, Bunkyo, Tokyo 113, Japan; Eng.) -Nuesgen 03-033