Satoru Ikegami

Asymmetric synthesis of α-amino acids by alkylation of N-[N-bis-(methylthio)methyleneglycyl]-2,5-bis(methoxymethoxymethyl)pyrrolidine and enantioselective synthesis of protected (2S,9S)-2-amino-8-oxo-9,10-epoxydecanoic acid

Abstract Highly diastereoselective alkylation (96% de) of α-lithiated N -[ N -bis(methylthio)methyleneglycyl]- trans -2, 5-bis(methoxymethoxymethyl)pyrrolidine and subsequent hydrolysis gave various α-amino acids of high optical purity. An unusual amino acid (2 S ,9 S )-2-amino-8-oxo-9,10-epoxydecanoic acid was also synthesized enantioselectively in its N -protected form by using the alkylation of the above chiral glycine amide and asymmetric epoxidation as means of introducing C2 and C9 asymmetric centers, respectively. Aldol condensation reaction of the same lithiated glycine amide was also examined.

Asymmetric synthesis of α-amino acids by alkylation of a glycine amide derivative bearing chiral 2,5-disubstituted pyrrolidine as an amine component

Abstract Highly diastereoselective alkylatlon (≥96% de) of α-lithiated N -[ N ′-bis(methylthio)- methyleneglycyl)- trans -2.5-b1s(methoxymethoxymethyl ) pyrrolidine and subsequent hydrolysis gave α-amino acids of high optical purity. An unusual amino acid (2 S ,9 S )-2-amino-8-oxo-9,10- epoxydecanoic acid was synthesized in its N -protected form as an application of the method.

A formal synthesis of aplysiatoxin: enantioselective synthesis of kishi's aldehyde

Abstract This paper describes the enantioselective synthesis of key fragments (12, 18, 24, and 35) for the synthesis of aplysiatoxin (1a), a potent cancer promoter, and their convergent assembly to Kishis aldehyde (2). Since 2 has already been transformed into 1a in a short step, its synthesis constitutes a formal total synthesis of 1a Synthesis of fragments of aplysiatoxin (1a) and their convergent assembly to the key intermediate, Kishis aldehyde (2), for the synthesis of 1a are described.

Synthesis of aplysiatoxin: stereoselective synthesis of key fragments

Abstract Stereoselective synthesis of key fragments for the synthesis of aplysiatoxin has been achieved. All the stereogenic carbons contained in fragments B≈E were elaborated on the basis of [2,3] Wittig rearrangement and titanium-mediated asymmetric epoxidation.

Stereoselectivity in [2,3]wittig rearrangement of isopropyl [(2E)-1 -(ω-benzyloxyalkyl)-2-butenyl]oxyacetate. Preparation of potent building blocks for the synthesis of polyoxo compounds

Abstract The stereochemistry of [2,3]Wittig rearrangement of isopropyl [(2 E )-1-(ω-benzyloxyalkyl)-2-butenyl]oxyacetates was found to depend on the position of benzyloxy group and the metal ion used, and in some suitable combinations, ( syn , E )- or ( syn , Z )-product was obtained with high selectivity.

A formal total synthesis of aplysiatoxin

Abstract A total synthesis of aplysiatoxin was achieved formally by construction of Kishis intermediate 13 which carried all the stereochemistry required for the synthesis of aplysiatoxin, from four fragments described in the preceding communication.

Stereoselective synthesis of the (±)-Ireland alcohol

Abstract The Ireland alcohol, a key intermediate for the synthesis of tirandamycin A, was prepared in a stereoselective manner, where titanium-mediated [2,3]Wittig rearrangement and iodolactonization were used as key steps for the construction of four consecutive asymmetric centers.