Indole-3-pyruvic acid oxime ethers and thieno analogues by Heck cyclisation. Application to the synthesis of thia-tryptophans
作者:David Wensbo、Salo Gronowitz
DOI:10.1016/0040-4020(96)00909-x
日期:1996.11
thienoamines (16,18,20) employing methyl or benzyl oxime ethers of ethyl (E)-2-oxo-5-bromo-3-pentenoate 2a, followed by palladium-catalysed Heck cyclisation yielded oxime ethers of Bz-substituted ethyl indole-3-pyruvates (15a-f) and thienopyrroles (17,19,21–23). Attempted conversion of 2a into the corresponding tosyl hydrazone or oxime resulted in formation of pyridazine (10) and oxazine (13) derivatives.
Asymmetric synthesis of differentially protected meso-2,6-diaminopimelic acid
作者:John L. Roberts、Cecil Chan
DOI:10.1016/s0040-4039(02)01844-0
日期:2002.10
meso-2,6-Diaminopimelic acid, an important linking component of bacterial cell walls and a biosynthetic precursor of L-lysine has been prepared differentially protected in a stereospecific manner from both L-aspartic and L-glutamic acid. The key step to establish the second chiral center involves the asymmetric reduction of a pyruvate moiety with Alpine-Borane(R). S-2-Amino-6-oxopimelic acid, the hydrolyzed open chain form of tetrahydrodipicolinic acid, a biosynthetic precursor of meso-2,6-diaminopimelic acid, was also prepared via deprotection of the key pyruvate intermediate. (C) 2002 Elsevier Science Ltd. All rights reserved.