Synthesis and Structural Revision of the Fungal Tetramic Acid Metabolite Spiroscytalin



Spiroscytalin, a natural 3-spirotetramic acid of hitherto uncertain absolute configuration, was synthesized for the first time by a one-pot Knoevenagel–IMDA reaction of an l-phenylalanine-derived tetramic acid and (R)-2-methyl-deca-6E,8E-dienal. Its absolute ...

Solvolytic Behavior of Aryl and Alkyl Carbonates. Impact of the Intrinsic Barrier on Relative Reactivities of Leaving Groups



The effect of negative hyperconjugation on the solvolytic behavior of carbonate diesters has been investigated kinetically by applying the LFER equation log k = sf(Ef + Nf). The observation that carbonate diesters solvolyze faster than the corresponding carbo...

Total Synthesis of Lycopladine A and Carinatine A via a Base-Mediated Carbocyclization



A concise, enantioselective synthesis of lycopladine A and carinatine A is presented. Our synthetic approach hinges on the recently developed mild carbocyclization of ynones to furnish the hydrindane core of the alkaloids. Their pyridine ring was efficiently ...

Total Synthesis of Cardiolipins Containing Chiral Cyclopropane Fatty Acids



Cardiolipin (CL) is a phospholipid located in both the eukaryotic mitochondrial inner membrane and the bacterial cell membrane. Some bacterial CLs are known to contain cyclopropane moieties in their acyl chains. Although the CLs are thought to be involved in ...

Synthesis of Spiro[indazole-3,3′-indolin]-2′-ones via [3 + 2] Dipolar Cycloaddition of Arynes with 3-Diazoindolin-2-ones and Indazolo[2,3-c]quinazolin-6(5H)-ones by Subsequent Thermal Isomerization



An efficient protocol for facile construction of spiro[indazole-3,3′-indolin]-2′-ones was developed via [3 + 2] dipolar cycloaddition of arynes with 3-diazoindolin-2-ones under mild conditions in excellent yields. Subsequent thermal isomerization of the spiro...

Pathways in the Degradation of Geminal Diazides



The degradation of geminal diazides is described. We show that diazido acetates are converted into tetrazoles through the treatment with bases. The reaction of dichloro ketones with azide anions provides acyl azides, through in situ formation of diazido keton...

Cobalt(II)-Catalyzed Isocyanide Insertion Reaction with Sulfonyl Azides in Alcohols: Synthesis of Sulfonyl Isoureas



A Co(II)-catalyzed isocyanide insertion reaction with sulfonyl azides in alcohols to form sulfonyl isoureas via nitrene intermediate has been developed. This protocol provides a new, environmentally friendly, and simple strategy for the synthesis of sulfonyl ...

Hypervalent Iodine(III)-Promoted Phenyl Transfer Reaction from Phenyl Hydrazides to Nitriles



A useful transformation of nitriles to N-phenyl amides has been achieved through a novel intermolecular phenyl transfer reaction from phenyl hydrazides and N-addition to nitriles in the presence of PIFA under mild and solvent-free conditions. This cross-coupl...

Matsutakone and Matsutoic Acid, Two (Nor)steroids with Unusual Skeletons from the Edible Mushroom Tricholoma matsutake



Matsutakone (1), a novel sterol with an unprecedented polycyclic ring system, together with a new norsteroid matsutoic acid (2) were isolated from the fruiting bodies of Tricholoma matsutake. Their structures and absolute configurations were assigned by exten...

Diastereoselective Synthesis of CF3-Containing Vicinal Diamines



The highly diastereoselective synthesis of CF3-containing vicinal diamines by a convenient two-step procedure without the need to isolate the intermediate products is described.