Conformational studies of two new brassinosteroid analogues with a 22,23-trans diol function

22,24-Diepiteasterone (3) and 23,24-diepiteasterone (4) were synthesized st arting from a mixture of the corresponding (22S,23S)- and (22R,23R)-epoxide s. Using detailed NOE investigations and molecular dynamic simulations with explicit solvent, the preferred conformations of both compounds were deter mined in solution. For both compounds 3 and 4 a preferred conformation of t he side chain was found. For 4, by X-ray analysis the conformation in cryst alline state was determined which differs distinctly from that in solution.