220407-98-7Relevant academic research and scientific papers
Total synthesis of the cytotoxic threo, trans, erythro, cis, threo Annonaceous acetogenin trilobin
Marshall, James A.,Jiang, Hongjian
, p. 971 - 975 (2007/10/03)
A synthesis of trilobin, a new stereochemical varient of the adjacent bis-tetrahydrofuran subgroup of the Annonaceous acetogenins, is described. The synthesis involves three stereochemically defining carbon-carbon bond- forming steps. The first of these introduces the C23-C24 stereocenters and the left side chain by means of an S(E),2' addition of the nonracemic 11- carbon γ-oxygenated allylic indium reagent derived from the α-oxygenated allylic stannane 4 to a C24-C16 core aldehyde 3. The second develops the C15- C16 stereocenters and a segment of the right chain through BF3-promoted S(E)2' addition of the nonracemic 6-carbon γ-oxygenated allylic stannane 11 to the C16-C34 aldehyde 10. The third employs the addition of the dialkylzinc reagent 17 to the C10-C34 aldehyde 15 in the presence of a chiral bis- sulfonamide catalyst to establish the C10 stereocenter while adding the C1- C9 residue of the right chain. The C36 stereocenter and the butenolide are appended through condensation of the C1-C34 ester with the protected (S)- lactaldehyde 23.
