Unexpected Results in the Reduction of Tetracyclic Enamides. Structure, Stereochemistry and Conformation of a 20b-Hydroperoxyimine
摘要:
Reduction of N(b)-allyl-20-ethyltetracyclic enamide (7) with lithium aluminium hydride afforded the expected enamine (12) and 4a-oxoethylhexahydrocarbazolones (18a,b). Reduction of N(b)-unsubstituted enamide (6), under the same conditions, gave imine (9), enamine (11) and a 20beta-hydroperoxytetracyclic imine (19) resulting from the peroxydation of 9 and 11. The C-20 stereochemistry of 19 was established by means of 2D H-1 nmr and NOE difference spectroscopy.
Deoligomerization: A New Route to Lactams from Unsaturated Amides via Radical Oligomerization
作者:Li Liu、Xing Wang、Chaozhong Li
DOI:10.1021/ol027428i
日期:2003.2.1
[reaction: see text] Triethylborane-initiated atom transfer radical oligomerization of N-allyl or N-(3-butenyl)iodoacetamides followed by treatment with hydrochloric acid and subsequent neutralization with K(2)CO(3) led to the formation of the corresponding 5-hydroxyl-substituted delta-lactams or caprolactams, respectively. This oligomerization-deoligomerization sequence serves as an alternative to