OPTICAL-ROTATORY DISPERSION STUDIES .135. SYNTHESIS AND CHIROPTICAL PROPERTIES OF (S)-(3-H-2-1)-2,2-DIMETHYLCYCLOBUTANONE AND (R)-(3-H-2-1)-2,2-DIMETHYLCYCLOBUTANONE - EVIDENCE FOR CONFORMATIONAL EFFECTS IN SUBSTITUTED CYCLOBUTANONES
OPTICAL-ROTATORY DISPERSION STUDIES .135. SYNTHESIS AND CHIROPTICAL PROPERTIES OF (S)-(3-H-2-1)-2,2-DIMETHYLCYCLOBUTANONE AND (R)-(3-H-2-1)-2,2-DIMETHYLCYCLOBUTANONE - EVIDENCE FOR CONFORMATIONAL EFFECTS IN SUBSTITUTED CYCLOBUTANONES
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DOI：
10.1021/ja00346a050
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发表时间：
1983-01-01
影响因子：
15
通讯作者：
DJERASSI, C
中科院分区：
文献类型：
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作者：
HARRIS, RN;SUNDARARAMAN, P;DJERASSI, C
14a R= H a. D2，Pd/C，EtOAc; B.高压MeOH; c. LíAlD 4; d. 03、MeOH; e. Me2 $; f. m-CPBA、CH2Cl2 g. RCC; h.（Ph3P）3RhCl、CH2Cl2; i. KOH。MeOH; j. Jones Ox.最常用的同位素。因此，我们对几种构象移动的手性氘代环己酮和环戊酮的合成和圆二色性数据进行了分析[3· 4]，发现除了一种环戊酮[4 b]外，氘相对于氢更倾向于占据具有较大非键空间相互作用的构象位置。此外，还计算了环己酮的椅式构象与环戊酮的扭曲构象之间的能量差，轴向和准轴向氘的能量差约为1-10卡/摩尔。3d，e虽然还没有关于手性完全由同位素取代引起的旋光环丁酮的圆二色性研究的报道，但Conia和Goré 5报道了一系列烷基化和溴化环丁酮的手性研究，我们报道了一系列烷基取代环丁酮的磁性圆二色性。6最近，CD和ORD光谱的（f？）- 2-甲基环丁酮。21从环丁酮1-3、5的CD研究中，
14a R= H a. D2, Pd/C, EtOAc; b. hv. MeOH; c. LíAlD4; d. 03, MeOH; e. Me2 $; f. m-CPBA, CH2C12i g. RCC; h.(Ph3P) 3RhCl, CH2C12; i. KOH. MeOH; j. Jones Ox. most commonly employed isotope. Thus we have reported3· 4 the synthesis and CD data of several conformationally mobile, chirally deuterated cyclohexanones and cyclopentanones and have found with the exception of one cyclopentanone4b that deuterium relative to hydrogen prefers to occupy a conformational position having the greater nonbonded steric interactions. Furthermore, the energy differences between chair conformations in cyclohexanones and twist conformations in cyclopentanones were calculated tobe on the order of 1-10 cal/mol infavor of axial and quasi-axial deuterium. 3d, eThough there have been no reports of CD studies on optically active cyclobutanones in which the chirality is solely due to isotopic substitution, Conia and Goré5 have reported chiroptical studies on a series of alkylated and brominated cyclobutanones and we have reported magnetic circular dichroism properties of a series of alkyl substituted cyclobutanones. 6 More recently, the CD and ORD spectra of (f?)-2-methylcyclobutanone have been reported. 21 From the CD studies of cyclobutanones 1-3, 5 a consistent trend