Total synthesis of the polyether antibiotic ionomycin
作者:David A. Evans、Robert L. Dow、Thomas L. Shih、James M. Takacs、Robert Zahler
DOI:10.1021/ja00169a042
日期:1990.6
A convergent asymmetric synthesis of the calcium ionophore ionomycin has been achieved through a route that is outlined below. The four illustrated subunits, which comprise the c,-C,,-,, CI)-&r cI&22, and C=-C32 portions of ionomycin,
Stereoselective Synthesis of 2,6-<i>cis</i>-Tetrahydropyrans through a Tandem Allylic Oxidation/Oxa-Michael Reaction Promoted by the<i>gem</i>-Disubstituent Effect: Synthesis of (+)-Neopeltolide Macrolactone
作者:Hyoungsu Kim、Yongho Park、Jiyong Hong
DOI:10.1002/anie.200903690
日期:2009.9.28
protecting groups is one highlight of a concise and efficient synthesis of (+)‐neopeltolide macrolactone on the basis of the title tandemreaction and dithiane coupling reactions (see scheme). The gem‐disubstituent effect of the dithiane moiety promoted the oxa‐Michael reaction following allylic oxidation to ensure the efficient synthesis of the 2,6‐cis‐tetrahydropyran and high diastereoselectivity.
Synthesis of Methyl <i>N</i>-Boc-(2<i>S</i>,4<i>R</i>)-4-methylpipecolate
作者:Kuo-yuan Hung、Paul W. R. Harris、Margaret A. Brimble
DOI:10.1021/jo102038q
日期:2010.12.17
An efficient stereoselective synthesis of fully protected (2S,4R)-4-methylpipecolic acid has been developed. The synthesis was achieved by initial asymmetric a-alkylation of glycine with a chiral iodide, affording the linear precursor as a single stereoisomer. Subsequent aldehyde formation using OsO4/NaIO4 followed by immediate intramolecular cyclization afforded an enamine that was then subjected to hydrogenation to give the final compound in 23% yield over 10 steps.
EVANS, DAVID A.;DOW, ROBERT L.;SHIH, THOMAS L.;TAKACS, JAMES M.;ZAHLER, R+, J. AMER. CHEM. SOC., 112,(1990) N3, C. 5290-5313
作者:EVANS, DAVID A.、DOW, ROBERT L.、SHIH, THOMAS L.、TAKACS, JAMES M.、ZAHLER, R+