Divergent Asymmetric Total Syntheses of (−)-Alloaristoteline and (+)-Aristoteline via Directed Indolization Strategies

A divergent asymmetric synthetic route to (−)-alloaristoteline and (+)-aristoteline is described. The key doubly bridged tricyclic enol triflate common intermediate prepared via enantioselective deprotonation and stepwise annulation was successfully bifurcated to complete the first completely synthetic construction of the titled natural alkaloids upon strategic implementation of the late-state directed indolization methods

Total Synthesis of (±)-Crinine via the Regioselective Stille Coupling and Diels−Alder Reaction of 3,5-Dibromo-2-pyrone

The regioselective synthesis and Diels−Alder cycloaddition of 3-(3,4-methylenedioxyphenyl)-5-bromo-2-pyrone provided a new synthetic route to crinine. The vinyl bromide group can be used as a handle for further derivatization

Total Synthesis of (±)-Joubertinamine from 3-(3,4-Dimethoxyphenyl)-5-bromo-2-pyrone

The regioselective synthesis and Diels−Alder cycloaddition of 3-(3,4-dimethoxyphenyl)-5-bromo-2-pyrone provided a new efficient synthetic route to joubertinamine (9.6% total yield over 10 steps)

Synthesis of Two Bicyclic Surfactants Which Form Reversed Micelles Capable of Selective Protein Extraction

Synthesis of Two Bicyclic Surfactants Which Form Reversed Micelles Capable of Selective Protein Extractio

Total Synthesis of (−)-Neocosmosin A via Intramolecular Diels–Alder Reaction of 2‑Pyrone

A new synthetic route to (−)-neocosmosin A was devised by elaboration of intramolecular Diels–Alder (IMDA) cycloaddition of 2-pyrone containing a bromopropiolate group as the dienophile. The IMDA reaction was accompanied by cycloreversion of carbon dioxide to give benzannulated macrolide with two bromide groups at C14 and C16. Installation of the pinacolboryl groups and oxidations allowed completion of the total synthesis of (−)-neocosmosin A

Tandem Diels−Alder Cycloadditions of 2-Pyrone-5-acrylates for the Efficient Synthesis of Novel Tetracyclolactones

Readily prepared from the regioselective Pd-catalyzed coupling reactions of 3,5-dibromo-2-pyrone, 3-bromo-2-pyrone-5-carboxylates undergo tandem uninterrupted sequential Diels−Alder cycloaddition reactions with allyl vinyl ethers in a highly regio- and stereoselective fashion to provide a series of novel tetracyclolactones in good yields

Technetium Complexes for the Quantitation of Brain Amyloid

Technetium Complexes for the Quantitation of Brain Amyloi

A Scalable Route to Trisubstituted (<i>E</i>)-Vinyl Bromides

An effective, readily scalable two-step synthesis of trisubstituted (E)-vinyl bromides involving bromination of α,β-unsaturated lactones followed by hydrolytic fragmentation has been developed. Several trisubstituted (E)-vinyl bromides, including multigram quantities of (+)-(E)-4-bromo-2-methyl-3-pentenol, a synthetic intermediate required for the C(8)−C(11) moieties of (+)-tedanolide (1) and (+)-13-deoxytedanolide (2), illustrate the utility of this protocol