226915-77-1

Upstream product

• 6089-04-9 3-(tetrahydropyran-2'-yloxy)propyne 
• 501-53-1 benzyl chloroformate 
• 110-87-2 3,4-dihydro-2H-pyran 

Downstream Products

• 226915-81-7 4-[(E)-(3-Phenyl-acryloyl)oxy]-but-2-ynoic acid benzyl ester 
• 226915-79-3 benzyl 4-hydroxybut-2-ynoate 

Relevant academic research and scientific papers

Gold-Catalyzed Bicyclic and [3+2]-Annulations of Internal Propargyl Alcohols with Nitrones and Imines To Yield to Two Distinct Heterocycles

A gold-catalyzed synthesis of 1,3-dihydrooxazolo[3,4-a]indoles from 1-oxo-3-yn-4-ols and nitrones is described; this new bicyclic annulation presents the first examples that internal alkynes can react with nitrones to undergo an oxoarylation route. DFT calculations indicate a [3,3]-sigmatropic shift of initial alkenylgold intermediates to elude the intermediacy of gold carbenes. We also developed new [3+2]-annulations of the same 1-oxo-3-yn-4-ols with imines, yielding oxazolidin-4-ylidene derivatives efficiently. The tethered alcohols of these 1-oxo-3-ynes allow trapping of their metastable 2-azadienium intermediates to enable a novel annulation. Our mechanistic analysis indicates that the two products, despite their structural relevance, are produced from two independent systems. (Figure presented.).

A facile Diels-Alder route to dihydronaphthofuranones

An efficient, multigram-scale synthesis of dihydronaphthofuranone 1 using a novel aryl intramolecular Diels-Alder reaction of propargyl trans- cinnamate 8 is described. Catalytic reduction of 1 gave the cis-fused tetrahydronaphthofuranone derivative 2. (C) 2000 Elsevier Science Ltd.

Catalytic (3+2) Palladium-Aminoallyl Cycloaddition with Conjugated Dienes

We describe the design and application of tailored aminoallyl precursors for catalytic (3+2) cycloaddition with conjugated dienes via a Pd-aminoallyl intermediate. The new cycloaddition reactions override the conventional (4+3) selectivity of aminoallyl cation cycloaddition through a sequence of Pd-allyl transfer and ring closure. A variety of highly substituted or fused pyrrolidine rings were synthesized using the cycloaddition, and can further undergo [1,3] N-to-C rearrangement to five-membered carbocycles with a different palladium catalyst. The utility of the (3+2) cycloaddition is also demonstrated by the preparation of various derivatives from the bicyclic pyrrolidine products.

THROMBIN RECEPTOR ANTAGONISTS

Heterocyclic-substituted tricyclics of formula (I) or a pharmaceutically acceptable salt thereof, wherein: the single dotted line represents an optional double bond; the double dotted line represents an optional single bond; n is 0-2; Q is optionally subs

Generation, electrocyclic ring opening, and unprecedented conversion of a 3-acylaminoazetinone into cis-3,4-disubstituted azetidinones

An attempt to synthesize the nucleus of cefaclor by insertion of an appropriately functionalized rhodium carbene into a β-lactam N-H bond leads instead to attack at sulfur, followed by fragmentation into a four-membered thietanone and a four-membered 3-acylaminoazetinone. The azetinone undergoes electrocyclic ring opening, with a calculated half-life of 11 s at 40°C, to a trans-disubstituted vinyl isocyanate, but can be trapped by saturated, unsaturated allylic and benzylic alcohols to form 3,4-disubstituted azetidinones in which the cis- isomer predominates.