Asymmetric Synthesis of Lycoperdic Acid.

Visible‐Light‐Induced Dearomatizations

“…Furan derivative 114 , which was readily prepared from 5‐bromofurfural and ( S )‐aspartic acid dimethyl ester, was subjected to a dearomative photocyclization to effectively construct a spirobutenolide fused to pyrrolidine ( 115 ). Subsequent hydrogenation provided the butyrolactone 116 , which could be further transformed to ( S )‐(+)‐lycoperdic acid ( 117 ) by a route described by Yoshifuji …”

Catalytic Enantioselective Total Synthesis of (+)–Lycoperdic Acid

“…(+)-Lycoperdic acid ( 1 ) was isolated from a mushroom Lycoperdon perlatum by Rhugenda-Banga et al It is an amino acid that shares structural similarities with both l -glutamic acid ( 2 ) and dysiherbaines ( 3a , 3b , Figure ). , The dysiherbaines are well-known ionotropic glutamate receptor binders, , a fact which has raised questions about the biological activity of (+)- 1 over the years. − …”

“…To date, there are seven total syntheses and one formal synthesis for (+)- 1 . − Most of them rely on either chiral pool or chiral auxiliaries to set the stereochemistry at C2 and C4 (Figure ). Very recently, the Oikawa group disclosed an approach where catalytic enantioselective hydrogenation was used to control the stereochemistry at C2 of (+)- 1 , but the construction of C4 was not stereoselective …”

An Efficient Transformation of Cyclic Ene-carbamates into .OMEGA.-(N-Formylamino)carboxylic Acids by Ruthenium Tetroxide Oxidation

“…The first example of this type of reaction was described by Desai and co-workers, 5) who reported one case that attempted the cleavage of a CϭC bond in steroidal enamines. Torii and co-workers 6) revealed the procedure for the RuO 4 oxidative cleavage of enolic olefins including two six-membered nitrogen-containing heterocyles that afforded the carbonyl compounds under the conditions using the substrate in a suspension of CCl 4 and H 2 O in the presence of RuO 2 · xH 2 O and NaIO 4 .On the other hand, we have been working on the transformation of cyclic [7][8][9] and acyclic [10][11][12] N-acyl amines into the corresponding lactams and imides including the natural products [13][14][15][16][17] by the RuO 4 oxidation. The double layer oxidation method using a catalytic amount of RuO 2 hydrate, an excess of a NaIO 4 aqueous solution and ethyl acetate system was established for these purposes in our laboratory.…”

“…On the other hand, we have been working on the transformation of cyclic [7][8][9] and acyclic [10][11][12] N-acyl amines into the corresponding lactams and imides including the natural products [13][14][15][16][17] by the RuO 4 oxidation. The double layer oxidation method using a catalytic amount of RuO 2 hydrate, an excess of a NaIO 4 aqueous solution and ethyl acetate system was established for these purposes in our laboratory.…”