Higher-order cycloaddition reactions in synthesis. Asymmetric assembly of the C5-C11 segment of the ansa bridge of streptovaricin D

Article abstract of DOI:10.1016/S0040-4039(98)01183-6

Auxiliary-controlled, asymmetric Cr(0)-promoted [6π+4π] cycloaddition followed by a ring fragmentation sequence afforded the C5-C11 segment of the ansa bridge found in the ansamycin antibiotics streptovaricin C, D and damavaricin D.