Crystal and molecular structure and absolute configuration of maytansine (3-bromopropyl) ether

摘要: The molecular structure and absolute configuration of maytansine (Ia) have been found from a three-dimensional single-crystal X-ray analysis its (3-bromopropyl) ether (Ib). Crystals are orthorhombic, space group P212121 with a= 24·239(4), b= 16·044(4), c= 10·415(2)A, Z= 4. was solved by the heavy-atom method refined Fourier least-squares methods to R 0·101 for 927 independent reflections measured counter diffractometry. established anomalous dispersion method.The molecule contains 19-membered ring nitrogen-containing aliphatic portion bridging substituted phenyl in 1,3-ansa-fashion. shows similarities those ansamycin antibiotics, but has novel epoxide, carbinolamine ether, aryl halide functions.