DMSO‐Aided o‐Iodoxybenzoic Acid (IBX) Oxidation of Fmoc‐Protected Amino Alcohols
摘要:
A fast and highly convenient procedure for the formation of Fmoc-protected amino aldehydes from the corresponding alcohols using 1.1 equiv. of IBX in the presence of dimethylsulfoxide (DMSO) is discussed. This procedure leads to the clean synthesis of Fmoc-amino aldehydes in excellent yields with less than 1% epimerization and with no chromatography required for purification.
2-alkenyl sulfoximines for the synthesis of highlysubstituted aza(poly)cyclic ring systems is described. The method relies on a one-pot combination of a reagent-controlled allyl transfer reaction to alpha- or beta-amino aldehydes, followed by a Michael-type cyclization of the intermediate vinyl sulfoximines generated in the first step. The sulfur-free target compounds are preferentially obtained by
The resolution of 2-amino alcohols protected by urethane-type groups either via porcinepancreaticlipase (PPL) hydrolysis of the corresponding racemic acetates or via PPL catalyzed transesterification of racemic alcohols was studied. In both cases, Boc protecting group led to better chemical yields and enantiopurities than Z and Fmoc protecting groups. Furthermore, a simple and efficient method for
oxidative cross-coupling of α-amino ketones with a wide range of alcohols is described. Using a combination of air and dimethyl sulfoxide (DMSO) as oxidants, the protocol allows an efficient synthesis of α-carbonyl N,O-acetals with high functional group tolerance and enables the late-stage introduction of α-amino ketones into biorelevant alcohols. Moreover, the present method can be used in the coupling of
An effective synthesis of N-(9-fluorenylmethyloxycarbonyl) .alpha.-amino aldehydes from S-benzyl thioesters
作者:Pak T. Ho、Kheh Yong Ngu
DOI:10.1021/jo00060a056
日期:1993.4
Antibacterial activity of quinolone–Macrocycle conjugates
作者:Elizabeth A. Jefferson、Eric E. Swayze、Stephen A. Osgood、Alycia Miyaji、Lisa M. Risen、Lawrence B. Blyn
DOI:10.1016/s0960-894x(03)00285-3
日期:2003.5
Novel quinolone-macrocycle conjugates displayed submicromolar antibacterial activity against Escherichia coli and Staphylococcus aureus bacterial strains. An analogous open-chain structure was not active at 100 muM against the same pathogenic strains. (C) 2003 Elsevier Science Ltd. All rights reserved.