Chemical Synthesis of (22E)-3.ALPHA.,6.ALPHA.,7.ALPHA.,12.ALPHA.-Tetrahydroxy-5.BETA.-chol-22-en-24-oic Acid and Its N-Acylamidated Conjugates with Glycine or Taurine: Precursors of the [22,23-3H] Labelled Tracers
Chemical Synthesis of (22E)-3.ALPHA.,6.ALPHA.,7.ALPHA.,12.ALPHA.-Tetrahydroxy-5.BETA.-chol-22-en-24-oic Acid and Its N-Acylamidated Conjugates with Glycine or Taurine: Precursors of the [22,23-3H] Labelled Tracers
Chemical Synthesis of (22E)-3.ALPHA.,6.ALPHA.,7.ALPHA.,12.ALPHA.-Tetrahydroxy-5.BETA.-chol-22-en-24-oic Acid and Its N-Acylamidated Conjugates with Glycine or Taurine: Precursors of the [22,23-3H] Labelled Tracers
(22E)-3α,6α,7α,12α-Tetrahydroxy-5β-chol-22-en-24-oic acid and its N-acylamidated conjugates with glycine or taurine were synthesized from cholic acid. The key reactions employed are: 1) degradation of the side chain in intermediary C24 3α,6α,7α,12α-tetrahydroxylated bile acid to the corresponding C22 23,24-dinor-aldehyde, followed by Wittig reaction with methyl (triphenylphosphoranylidene)acetate and 2) N-acylamidation of the unconjugated tetrahydroxy-Δ22-5β-cholenoic acid with glycine (or taurine) in the presence of diethylphosphorocyanide and triethylamine as coupling reagents.