actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,17-dione in 5-steps reactions with overall yield 63.3%. Consequently, a strategy was used to...actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,17-dione in 5-steps reactions with overall yield 63.3%. Consequently, a strategy was used to produce of 17-α-hydroxyl compound stereoselectively by addition 17-keto steroid with hydrogen cyanide, at the same time, the conditions of this asymmertric reaction were optimized. The titled compound and the intermediate were fully characterized by 1H, one dimension and two dimension 13C-nuclear magnetic resonance, and infrared spectrum. The results show that the rate of 17-α-hydroxyl compound isomeride is sensitively affected by the solution system and the best volume ratio of CH3OH to H2O is 36%. After the carbonyl and hydroxyl groups were protected by ethylenediol and vinyl butyl ether respectively, organometallic addition to CN group with CH3Li, androstance compound was converted to pregnane compound. After removing the protective groups by a mild hydrolytic procedure with high yield, the titled compound was obtained by esterified the above intermidiate. The new pathway gives a good purity of 98% as determined by high performance liquid chromatography.展开更多
The basic approximation of the MNDO method is applied to the SCF-MO theory of nu-clear magnetic shielding constants.Gauge-invariant atomic orbitais（GIAO）and derived equations are used to cal-culate NMR chemical shif...The basic approximation of the MNDO method is applied to the SCF-MO theory of nu-clear magnetic shielding constants.Gauge-invariant atomic orbitais（GIAO）and derived equations are used to cal-culate NMR chemical shifts.A more simple and effective calculation of integration for operators 1/r<sub>M</sub>,L<sub>M</sub> andL<sub>M</sub>/r<sub>M</sub> described in our previous paper is used.By proper selection of MNDO parameters together with thetwo-center approximation,a satisfactory agreement between computational and experimental <sup>13</sup>C and <sup>19</sup>F chemi-cal shifts is obtained for a representative set of fluorides.展开更多
文摘actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,17-dione in 5-steps reactions with overall yield 63.3%. Consequently, a strategy was used to produce of 17-α-hydroxyl compound stereoselectively by addition 17-keto steroid with hydrogen cyanide, at the same time, the conditions of this asymmertric reaction were optimized. The titled compound and the intermediate were fully characterized by 1H, one dimension and two dimension 13C-nuclear magnetic resonance, and infrared spectrum. The results show that the rate of 17-α-hydroxyl compound isomeride is sensitively affected by the solution system and the best volume ratio of CH3OH to H2O is 36%. After the carbonyl and hydroxyl groups were protected by ethylenediol and vinyl butyl ether respectively, organometallic addition to CN group with CH3Li, androstance compound was converted to pregnane compound. After removing the protective groups by a mild hydrolytic procedure with high yield, the titled compound was obtained by esterified the above intermidiate. The new pathway gives a good purity of 98% as determined by high performance liquid chromatography.
文摘The basic approximation of the MNDO method is applied to the SCF-MO theory of nu-clear magnetic shielding constants.Gauge-invariant atomic orbitais（GIAO）and derived equations are used to cal-culate NMR chemical shifts.A more simple and effective calculation of integration for operators 1/r<sub>M</sub>,L<sub>M</sub> andL<sub>M</sub>/r<sub>M</sub> described in our previous paper is used.By proper selection of MNDO parameters together with thetwo-center approximation,a satisfactory agreement between computational and experimental <sup>13</sup>C and <sup>19</sup>F chemi-cal shifts is obtained for a representative set of fluorides.
