A novel entry to the synthesis of diazoacetates is disclosed. A variety of diazoacetates were synthesized from the corresponding bromoacetates by treatment with N,N'-ditosylhydrazine in moderate to high yields. Ease of operation with the stable crystalline reagent as well as a short reaction time offer a useful alternative to the conventional methods.

Optically pure hinckdentine A was synthesized on a 300 mg scale via an asymmetric catalysis-based strategy. The key steps to the first asymmetric synthesis involved (i) enantioselective dearomative cyclization of an achiral N-acyl indole that allowed for the efficient construction of the key polycyclic indoline intermediate with a crucial tetrasubstituted stereogenic carbon center, (ii) Beckmann fragmentation-mediated ring expansion, (iii) rearrangement-based introduction of an anilinic nitrogen atom, (iv) regioselective tribromination, and (v) final closure of the cyclic amidine moiety.

The first total synthesis of gelsemoxonine (1) has been accomplished. Divinylcyclopropane-cycloheptadiene rearrangement of the highly functionalized substrate was successfully applied to assemble the spiro-quaternary carbon center connected to the bicyclic seven-membered core structure. A one-pot isomerization reaction of the α,β-unsaturated aldehyde to the saturated ester via the TMSCN-DBU reagent combination allowed a facile diastereoselective introduction of the latent nitrogen functionality of the unique azetidine moiety.

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Azo compounds Q 0160 N,N'-Ditosylhydrazine: A Convenient Reagent for Facile Synthesis of Diazoacetates. -A general method for the preparation of a large variety of racemic and chiral diazoacetates is developed. -(TOMA, T.; SHIMOKAWA, J.; FUKUYAMA*, T.; Org. Lett. 9 (2007) 16, 3195-3197; Grad. Sch. Pharm. Sci., Univ. Tokyo, Bunkyo, Tokyo 113, Japan; Eng.) -R. Steudel 49-082

A variety of oximes were synthesized from the corresponding alcohols, alkyl halides, or alkyl sulfonates without using external oxidants. With this simple two-step procedure involving substitution with readily available TsNHOTBS and subsequent treatment with CsF, a range of oximes were prepared including the ones hardly preparable with conventional procedures.

Asymmetric total synthesis of batzelladine A (1) and batzelladine D (2) has been achieved. Our synthesis of batzelladines features 1) stereoselective construction of the cyclic guanidine system by means of successive 1,3-dipolar cycloaddition reaction and subsequent cyclization, 2) direct esterification of the bicyclic carboxylic acid 35 with the guanidine alcohol 8 or 59 to construct the whole carbon skeleton of batzelladines, and 3) one-step formation of the alpha,beta-unsaturated aldehyde 53 from the primary alcohol 47 with tetra-n-propylammoniumperruthenate (TPAP), providing an efficient route to the left-hand bicyclic guanidine alcohol of batzelladine A (1). With the synthetic compounds 1 and 2 in hand, their target protein was examined by using immobilized CD4 and gp120 affinity gels. The results indicated that batzelladines A (1) and D (2) bind specifically to CD4.

Six in one blow: Total syntheses of all the amathaspiramide alkaloids have been accomplished. Rapid construction of the diazaspiro[3.3]nonane core combined with regio‐ and diastereoselective reduction of the cyclic imide moiety with DIBAL established the route to the common structural motif. The late‐stage reduction of the lactam to an imine functionality mediated by Schwartz's reagent was the key to the streamlined syntheses.