Progress toward the assembly of the bicyclic theonellamide skeleton
作者:Jyoti P. Mukherjee、Joyeeta Roy、Chyree S. Batton、Saroj Yadav、Douglas Wong、Carol M. Taylor
DOI:10.1016/j.tet.2020.131127
日期:2020.4
synthesized in solution. Each ring was formed independently, providing insights into protectinggroup limitations, side reactions, and the optimal order of events to approach the formation of the bicyclic system. Ultimately, an undecapeptide was prepared, with the eastern ring formed. The twelfth aminoacid, an l-α-aminoadipic acid building block, was prepared and preliminary investigations into its attachment
Synthesis of Orthogonally Protected (2<i>S</i>)-2-Amino-adipic Acid (α-AAA) and (2<i>S</i>,4<i>R</i>)-2-Amino-4-hydroxyadipic Acid (Ahad)
作者:Saroj Yadav、Carol M. Taylor
DOI:10.1021/jo400558t
日期:2013.6.7
(2S,4R)-2-Amino-4-hydroxyadipic acid (Ahad) building block 45 was synthesized in 11 steps and 6.5% overall yield from commercially available materials. Key steps in stereocontrol were an asymmetric conjugate addition employing a proline-based catalyst and a syn-selective intramolecular-conjugate addition of an oxygen nucleophile to an alpha,beta-unsaturated ester. To enable incorporation of alpha-amino-adipic acid (alpha-AAA) and Ahad into peptides, a truly orthogonal protecting group scheme was developed, encompassing an allyloxycarbonyl (Alloc) carbamate for Na, a tert-butyl ester for the delta-COOH, an acetol ester for the alpha-COOH, and a tert-butyldimethylsilyl ether for the gamma-hydroxy group of Ahad.