226915-79-3

Upstream product

• 501-53-1 benzyl chloroformate 
• 226915-77-1 4-(tetrahydro-pyran-2-yloxy)-but-2-ynoic acid benzyl ester 

Downstream Products

• 226915-81-7 4-[(E)-(3-Phenyl-acryloyl)oxy]-but-2-ynoic acid benzyl ester 
• 473469-83-9 C₂₀H₁₅⁽²⁾HO₄ 
• 473469-85-1 C₂₀H₁₅⁽²⁾HO₄ 

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.).

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.

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.

3-(Optionally substituted-but-1-en-3-ynyl) cephalosporins

Compounds of general formula I STR1 (wherein R represents NH2 -- or an acylated or silylated amino group; R2 represents a hydrogen, halogen, alkyl, aryl, carboxyl or lower alkoxycarbonyl group; R3 is hydrogen or a carboxyl blocking group; B is >Sor>S→O (α- or β-); and the dotted line represents Δ2 or Δ3 unsaturation) and salts, solvates and esters thereof are described. Compounds where R3 is hydrogen, the dotted line represents Δ3 unsaturation and R is a group of formula STR2 (where Ra is an optionally substituted heterocyclic aryl group having one or more hetero atoms selected from S, N and O in the ring, Rb is an optionally substituted aryl group, Rc is hydrogen, acyl, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl or aralkyl, Rd is as defined for Ra or is an optionally substituted group and X is amino, hydroxyl, acylated hydroxyl, carboxyl or esterified carboxyl) and especially the compounds in which B is >S, have valuable antibiotic activities. Compounds in which the --CH=CH--C C--R2 group is in the trans configuration have been found to have good oral absorption. The remaining compounds of formula (I) are valuable as intermediates in processes for the preparation of the above active antibiotics, which processes are also described.