Absolute configuration of C_(20)H_(30)O_6Si, a species with a (1R, 5R)-8-oxabicyclo[3.2.1]octa-2, 6-diene core produced selectivity by the rhodium(II) octanoate catalyzed decomposition of a chiral vinyldiazomethane in the presence of furan

摘要

The compound under investigation crystallizes in the noncentrosymmetric monoclinic space group P2_1 with a = 9.1789(23), b = 6.6606(18), c = 17.6591(41) A, #beta# = 94.342(20) deg and Z = 2. The C_(20)H_(30)O_6Si molecule contains three chiral centers (one of which is of known configuration, based upon an (R)-pantolactone auxiliary group). We have determined the absolute configuration of this species (via the anomalous dispersion of Si relative to C and O) and show that it is consistent with the known configuration of the (R)-pantolactone moiety.