Research Projects
Grieco Group Overview
Our synthetic efforts are concentrated in two different areas: natural products total synthesis and medium effects in organic chemistry.
In the total synthesis areas, efforts are focused on several classes of biologically active natural products, including quassinoids, scytophycins, and saponins. Target molecules with which we are specifically involved include scytophycin C, tedanolide, and laulimalide.
Solvent effects have a profound influence on organic reactivity. For example, it has been shown that 5.0M lithium perchlorate in diethyl ether can have a dramatic effect on the reaction rate of [4+2] cycloaddition reactions as well as on the diastereoselectivity which accompanies the Diels-Alder reaction. The extension of this work to a general strategy for the construction of carbocyclic ring systems via intramolecular Diels-Alder reactions in highly polar media is being developed which features in situ generation of heteroatom-stabilized allyl cations which undergo subsequent [4+2] cycloaddition at ambient temperature.
The rigid oxabicyclo[3.2.1]octane has proven useful as a stereochemical control vehicle in the synthesis of natural products. Despite successes in this area of synthesis, the ability to introduce substituents into the bridgehead positions of rigid oxabicyclo[3.2.1] systems has met with little success. Through the agency of 5.0M lithium perchlorate in diethyl ether, one can exclusively add nucleophiles to the bridgehead position of oxabicyclic systems thus permitting the construction of functional motifs for use in organic synthesis. The potential of this methodology for generating complex \"dipropionate\" stereotriads, present in a large array of natural products, is under investigation.
Personnel:
Paul Grieco
Keywords:
Synthesis
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