The octant rule VIII.∗∗For paper VII, see D. A. Lightner, J. K. Gawroński and T. D. Bouman, J. Am. Chem. Soc., 102, in press. Variable temperature circular dichroism spectra of α-methyl- and methoxyl-substituted 5α-cholestan-2- and -3-ones
作者:D.A. Lightner、F.P.C. Eng
DOI:10.1016/0039-128x(80)90102-6
日期:1980.2
synthesized and their variable temperature circulardichroismspectra obtained and analyzed. Rotatory strength (R) values for alpha-axial and equatorial CH3 and OCH3 groups are determined by difference measurements with the parent ketone. The (small) equatorial CH3 R-values do not consistently follow the OctantRule. Axial OCH3 groups do not obey the OctantRule ("anti-octant" behavior) and impose a bathochromic
已经合成了2个α-和2个β-甲基和甲氧基-5α-胆甾烷-3-酮和3个α-和3个β-甲基-和甲氧基5α-胆甾烷-2-酮,并且它们的变温圆二色性获得并分析光谱。α轴和赤道CH3和OCH3基团的旋转强度(R)值是通过与母体酮的差异测量来确定的。(小)赤道CH3 R值未始终遵循八分法则。轴向OCH3基团不遵守Octant规则(“抗octant”行为),并在C = O n-pi过渡上施加红移。赤道OCH3组并非始终遵循八进制或“反八进制”行为。