Two polyhydroxylated piperidines have been prepared in short sequences from diacetone gluco- and allofuranose. The key step is a piezo-aza-Michael addition of diphenylmethanamine to enoates bearing a sugar moiety in the γ-position. The combination of ultra-high pressure associated to the presence of readily available sugars chiral pool led to the expected chiral amines in good yields and excellent stereoselectivities.
Diastereoselective synthesis of 1,2-O-isopropylidene-1,6-dioxaspiro[4,4]nonane applying the methodology of generation of radical cations under non-oxidizing conditions
作者:Fernando Sartillo-Piscil、Mónica Vargas、Cecilia Anaya de Parrodi、Leticia Quintero
DOI:10.1016/s0040-4039(03)00817-7
日期:2003.5
stereoselective synthesis of an optically pure spiroketal via an intramolecular tandem hydrogen abstraction reaction promoted by an alkoxy radical. Expanding the use of alkene radical cationunder non-oxidizing conditions in the synthetic scenario.
The undecose nucleoside antibiotics herbicidinC and aureonuclemycin are biologically highly active and represent challenging targets for total synthesis. Herein, the gradual evolution of our synthetic strategy toward these natural products is described in detail. The initial route encompasses metalate addition chemistry but suffers from poor stereochemical control. In contrast, the ultimately successful