Efficient syntheses of ¹³C‐labelled erythromycin biosynthetic intermediates. 2: (2<i>S</i>,3<i>S</i>,4<i>S</i>,5<i>R</i>,6<i>R</i>,7<i>R</i>)‐3,6,7‐trihydroxy‐2,4,6‐trimethyl[1‐¹³C]nonan‐5‐olide and <i>S</i>‐2‐acetylaminoethyl (2<i>R</i>,3<i>S</i>,4<i>S</i>,5<i>R</i>,6<i>S</i>,7<i>R</i>)‐3,5,6,7‐tetrahydroxy‐2,4,6‐trimethyl[1‐¹³C]nonanethioate

<jats:title>Abstract</jats:title><jats:p>The <jats:sup>13</jats:sup>C‐labelled putative erythromycin biosynthetic intermediates, ((2<jats:italic>S</jats:italic>,3<jats:italic>S</jats:italic>,4<jats:italic>S</jats:italic>,5<jats:italic>R</jats:italic>,6<jats:italic>R</jats:italic>,7<jats:italic>R</jats:italic>)‐3,6,7‐trihydroxy‐2,4,6‐trimethyl[1‐<jats:sup>13</jats:sup>C]nonan‐5‐olide and <jats:italic>S</jats:italic>‐2‐acetylaminoethyl (2<jats:italic>R</jats:italic>,3<jats:italic>S</jats:italic>,4<jats:italic>S</jats:italic>,5<jats:italic>R</jats:italic>,6<jats:italic>S</jats:italic>,7<jats:italic>R</jats:italic>)‐3,5,6,7‐tetrahydroxy‐2,4,6‐trimethyl[1‐<jats:sup>13</jats:sup>C]nonanethioate), which would be useful for the investigation of the chain elongation mechanism in erythromycin biosynthesis, were efficiently synthesized via aldol condensation of aldehyde derived from (2<jats:italic>S</jats:italic>,3<jats:italic>R</jats:italic>,4<jats:italic>R</jats:italic>,5<jats:italic>R</jats:italic>)‐<jats:italic>tert</jats:italic>‐butyldimethylsilyloxy‐5‐3,4‐<jats:italic>O</jats:italic>‐isopropylidene‐2,4‐dimethylheptanol, which was obtained in our previous work on erythromycin A synthesis, and sodium [1‐<jats:sup>13</jats:sup>C]propionate (after conversion to ester). Copyright © 2008 John Wiley & Sons, Ltd.</jats:p>