[reaction: see text] The enantioselective total synthesis of (+)-neosymbioimine was accomplished in 18 steps from (-)-(S)-citronellol utilizing an organocatalytic alpha-oxidation of aldehyde 6. The carbon core was constructed by a tandem Horner-Wadsworth-Emmons (HWE) reaction and an intramolecular Diels-Alder cyclization. All double bonds of 12 were made in a stereoselective manner by Wittig-type reactions. Selective formation of the monosulfate monoester was accomplished by one-pot excessive sulfation followed by kinetic hydrolysis of bissulfate 18 in 79% yield. 相似文献
The right bicycle : A concise formal synthesis of platencin was based on an efficient oxygen‐mediated palladium‐catalyzed cycloalkenylation of 1 to form a bicyclo[3.2.1]octane, and a deoxygenative rearrangement of tosylhydrazone 2 to construct the bicyclo[2.2.2]octane 3 . The total yield of the core structure 4 of platencin was 17.5 % for 13 steps from a commercially available compound. Ts=p‐toluenesulfonyl, TBS=tert‐butyldimethylsilyl, Piv=pivaloyl.
Glutamate gated postsynaptic receptors in the central nervous system (CNS) are essential for environmentally stimulated behaviours
including learning and memory in both invertebrates and vertebrates. Though their genetics, biochemistry, physiology, and
role in behaviour have been intensely studied in vitro and in vivo, their molecular evolution and structural aspects remain poorly understood. To understand how these receptors have evolved
different physiological requirements we have investigated the molecular evolution of glutamate gated receptors and ion channels,
in particular the N-methyl-D-aspartate (NMDA) receptor, which is essential for higher cognitive function. Studies of rodent NMDA receptors show that the
C-terminal intracellular domain forms a signalling complex with enzymes and scaffold proteins, which is important for neuronal
and behavioural plasticity 相似文献
