Synthese von ?-Acetyl-?-methylenpolyencarbons�ureestern
摘要:
The alpha-methylenpolyene carboxylic acids 1 and 2 are highly active against Gram-positive bacteria. If this activity arises from an interference with the cell membranes, then an abrupt change in biological properties is to be expected with growing chain length of simple model compounds. To make these tests possible, we describe here the synthesis of a series of homologue esters of type 40. Their synthesis was achieved by Wittig reactions of polyene alpha,omega-dialdehydes 6 with acetyl-methylentriphenylphosphoran 5a and the protected carboxymethylmethylen triphenylphosphonium salt 8.
Synthese von ?-Acetyl-?-methylenpolyencarbons�ureestern
摘要:
The alpha-methylenpolyene carboxylic acids 1 and 2 are highly active against Gram-positive bacteria. If this activity arises from an interference with the cell membranes, then an abrupt change in biological properties is to be expected with growing chain length of simple model compounds. To make these tests possible, we describe here the synthesis of a series of homologue esters of type 40. Their synthesis was achieved by Wittig reactions of polyene alpha,omega-dialdehydes 6 with acetyl-methylentriphenylphosphoran 5a and the protected carboxymethylmethylen triphenylphosphonium salt 8.
A Total Synthesis of Xestodecalactone A and Proof of Its Absolute Stereochemistry: Interesting Observations on Dienophilic Control with 1,3-Disubstituted Nonequivalent Allenes
作者:Toshiharu Yoshino、Fay Ng、Samuel J. Danishefsky
DOI:10.1021/ja064270e
日期:2006.11.1
A concise total synthesis of xestodecalactone A, utilizing a Diels-Alder strategy is described. The focal Diels-Alder reaction relied on an "ynoate" dienophile to rapidly assemble the required resorcylinic acid scaffold. During this study, Diels-Aldercycloaddition reactions involving 1,3-disubstituted nonequivalent allene dienophiles were studied, and some surprising results were encountered.
their prevalence in nature and their broad utility in pharmaceutical industry. Reported herein is an unprecedented noble‐metal‐ and oxidant‐free electrochemical method for the coupling of (hetero)arylamines with tethered alkynes to synthesize highly functionalized indoles, as well as the more challenging azaindoles.