The first enantiospecific synthesis of akaol A, a marine sesquiterpene quinol, has been achieved. Key steps of the synthetic sequence are the oxidative degradation of (-)-sclareol to a dinorlabdane ketoester, mediated by the ozone-lead(IV) acetate system, the diastereoselective α-methylation of a ketoaldehyde, followed by an intramolecular aldol condensation and the further Diels-Alder cycloadd...

The discovery and development of an efficient ene carbocyclization of 1,3-dicarbonyl compounds bearing pendent terminal alkyne substituents under 3-nitrobenzeneboronic acid catalysis is described. The reaction is efficient, easy to perform and general to a wide range of ketoester substrates.

Preliminary studies of a synthetic approach to the alkaloid stemofoline 1 are reported. Stereoselective cyclisation of the ketoester 14 gave the 1-butyl-2,8-bis(methoxycarbonyl)-8-azabicyclo[3.2.1]octane 21 in which the 2-methoxycarbonyl group is in the axial position. The analogous ketones 15, 18, and 19 were also cyclised to give the 8-azabicyclo[3.2.1]octanes 22-24 with axial electron-withdr...

Highly and homogeneously crosslinked poly(beta-ketoester) networks densely bearing robust nitroxide radicals were prepared via a click-type and stepwise Michael polyaddition. A half-battery cell composed of the thermally-cured radical network coatings displayed a rapid, reversible, and almost stoichiometric redox-activity even with a thickness of ca. 10 mum, which may be applicable as the elect...

General homogeneous conditions for the palladium-catalyzed synthesis of carbonyl compounds with tertiary carbon stereocenters at the alpha-position are reported. The highly reactive catalyst tolerates a variety of substrate substitution and functionality, and generates enantioenriched cyclic ketones from racemic allyl beta-ketoester starting materials.

[reaction: see text] This letter describes the insertion of rhodium carbenoids into thioindoles. C-10 thioindoles undergo fragmentation-coupling reactions when exposed to rhodium carbenoids. In an analogous fashion, ketoester- and malonate-substituted carbenoids have been found to insert into C-2 thioindoles. In contrast, vinylogous carbenoids were found to alkylate C-2 thioindoles at C-3.

Tertiary propargyl vinyl ethers armed with an electron-withdrawing group (amide or ester) at the tertiary propargylic position have been efficiently transformed into trisubstituted C(2)-chain functionalized furans. The metal-free domino transformation involves a microwave-assisted tandem [3,3]-propargyl Claisen rearrangement/5-exo-dig O-cyclization reaction. The manifold can be performed in a o...

An enantioselective phosphine-catalyzed transformation has been developed for the synthesis of chiral cyclobutene triesters and fluorinated spirocyclic compounds. The strategy involved a P(III)/P(V) redox cycling process, via in situ reduction phosphine oxide with phenylsilane. This catalytic methodology enabled functionalized cyclobutenes (24 examples, up to 94% ee). On occasion extension this...