145401-48-5Relevant articles and documents
Total synthesis of sphingofungin f by orthoamide-type Overman rearrangement of an unsaturated ester
Tsuzaki, Shun,Usui, Shunme,Oishi, Hiroki,Yasushima, Daichi,Fukuyasu, Takahiro,Oishi, Takeshi,Sato, Takaaki,Chida, Noritaka
, p. 1704 - 1707 (2015)
The total synthesis of sphingofungin F through the Overman rearrangement of an unsaturated ester, which is known to be an unsuitable substrate under standard conditions due to the competitive aza-Michael reaction, is described. The developed conditions enabled the ester to be compatible with the original Overman rearrangement, providing quick access to α,α-disubstituted amino acids by minimizing extra protecting group manipulations and redox reactions.
Synthesis of β-hydroxy-α,α-disubstituted amino acids through the orthoamide-type overman rearrangement of an α,β-unsaturated ester and stereodivergent intramolecular SN2′ reaction: Development and application to the total synthesis of sphingofungin F
Sugai, Tomoya,Usui, Shunme,Tsuzaki, Shun,Oishi, Hiroki,Yasushima, Daichi,Hisada, Shoko,Fukuyasu, Takahiro,Oishi, Takeshi,Sato, Takaaki,Chida, Noritaka
, p. 594 - 607 (2018/04/20)
The development of a two-step synthesis for β-hydroxy-α,α- disubstituted amino acid derivatives from cyclic orthoamide is reported. The first step is the orthoamide-type Overman rearrangement of an α,β-unsaturated ester to give a sterically hindered α,α-disubstituted amidoester. The α,β-unsaturated ester is known to be a challenging substrate in the conventional Overman rearrangement due to the competitive aza-Michael reaction. However, suppression of the aza-Michael reaction is realized by two factors; 1) the high reaction temperature, and 2) an alkyl substituent at the α-position. The second step is stereodivergent intramolecular SN2′ reaction for the installation of a hydroxy group at the β-position. Either syn- or anti-type SN2′ reaction is possible by simply changing the reaction conditions. The developed method can provide all four possible stereoisomers of the β-hydroxy-α,α-disubstituted amino acid, and is successfully applied to the total synthesis of sphingofungin F.
Total synthesis of sphingofungin F.
Lee, Kee-Young,Oh, Chang-Young,Ham, Won-Hun
, p. 4403 - 4405 (2007/10/03)
[reaction: see text] A concise, stereocontrolled synthesis of sphingofungin F was achieved. Key features involve diastereoselective oxazoline formation catalyzed by palladium(0), MgBr(2)-promoted gamma-alkoxy allylic stannane addition, and palladium(0)-ca
