A new approach for ¹¹C–C bond formation: Synthesis of 17<i>α</i>‐(3′‐[¹¹C]prop‐1‐yn‐1‐yl)‐3‐methoxy‐3,17<i>β</i>‐estradiol

Abstract

Abstract A new approach for 11 C–C bond formation via a Sonogashira‐like cross‐coupling reaction of terminal alkynes with [ 11 C]methyl iodide was exemplified by the synthesis of 17 α ‐(3′‐[ 11 C]prop‐1‐yn‐1‐yl)‐3‐methoxy‐3,17 β ‐estradiol. The LC‐purified title compound was obtained in decay‐corrected radiochemical yields of 27–47% ( n =8) based on [ 11 C]methyl iodide within 21–27 min after EOB. In a typical synthesis starting from 9.6 GBq [ 11 C]methyl iodide, 1.87 GBq of 17 α ‐(3′‐[ 11 C]prop‐1‐yn‐1‐yl)‐3‐methoxy‐3,17 β ‐estradiol was synthesized in radiochemical purity &gt;99%. The specific radioactivity ranged between 10 and 19 GBq/µmol, and the labeling position was verified by 13 C‐NMR analysis of the corresponding 13 C‐labeled compound. Copyright © 2003 John Wiley &amp; Sons, Ltd.