Determination of Absolute Configuration of Acyclic 1,2-Diols with Mo₂(OAc)₄. 1. Snatzke's Method Revisited

Abstract

The method employing dimolybdenum tetraacetate for the assignment of the absolute configuration of optically active 1,2-diols is thoroughly revisited and applied to several compounds, some of which were synthesized by asymmetric cis-dihydroxylation. No exceptions were found to the empirical rule relating the sign of the induced CD spectrum and the configuration of the substrate, whatever its structure and sterical requirements. To broaden the scope of the method, its applicability to critical situations commonly encountered with synthetic products is tested. It is demonstrated that the method can be applied on samples with low chemical and optical purity, and that it may lend itself as a means to estimate the ee. The roles of the water content of the sample and of the diol-to-dimolybdenum ratio are investigated.

Five 2-(2-Phenylethyl)chromones from Sodium Chloride-Elicited Aquilaria sinensis Cell Suspension Cultures

“…The absolute configurations of C-6 and C-7 were solved according to the method reported by Snatzke and Frelek [10]. DMSO solutions of 1 and dimolybdenum tetraacetate [Mo 2 (AcO) 4 ] were homogeneously mixed, and the induced circular dichroism (ICD) spectrum was recorded.…”

“…Additionally, feruloyl amides, nucleosides, and lignins have been extensively reported as being involved in plant defenses [25][26][27][28]. The identification of 2-(2-phenylethyl)chromones (1)(2)(3)(4)(5), feruloyl amides (6)(7)(8), nucleosides (9)(10)(11)(12)(13)(14), and (+)-syringaresinol (15) would be useful for further exploring the mechanism of agarwood formation. [13], N-trans-feruloyltyramine (6) [14], N-trans-feruloyloctopamine (7) [14], N-cis-feruloyltyramine (8) [14], N 6 -methyladenosine (9) [15], adenosine (10) [16], 2'-deoxy-D-adenosine (11) [16], thymidine (12) [17], 2'-deoxyuridine (13) [17], uridine (14) It is well known that biotic and abiotic stresses could adversely affect plant growth and subsequently cause the production of specific secondary metabolites for plant defense.…”

Bioactive Flavaglines and Other Constituents Isolated from Aglaia perviridis

“…According to a published procedure, 51,52 0.3 mg of compound 8 and 0.75 mg of Mo 2 (OAc) 4 were dissolved in 1.0 mL dry DMSO to give a solution, with the ligand to metal molar ratio being around 1.0:1.2. The electronic transitions of the metal complex in DMSO was monitored by CD measurement immediately in the UV/vis region of 200 to 450 nm after mixing (recording a spectrum every 10 min), until a stationary induced circular dichrosim (ICD) spectrum was observed around 30 min later.…”

“…In this case, a practical and reliable method developed by Snatzke and Frelek was employed to solve the problem. 51,52 After mixing compound 8 and dimolybdenum tetraacetate [Mo 2 (AcO) 4 ] in DMSO, a ligand-metal complex possessing an suitable chromophoric group was formed, for which the induced circular dichroism spectrum (ICD) was recorded and analyzed. According to Snatzke's theory, the absorption band around 310 nm (band IV) is one of these most reliably related to the absolute configuration of a diol derivative in the [Mo 2 (AcO) 4 ]-induced CD (ICD) spectrum, which possesses the same sign of torsional angle of the O-C-C-O unit in the favored conformation.…”

Two New Terpenoids from Endophytic Fungus Periconia sp. F-31

“…4). On the basis of the empirical rule of Snatzke's method (the dimolybdenum method), 11,12) in the Mo 2 (AcO) 4 -induced CD spectrum of 1, a negative Cotton effect at 317 nm and positive Cotton effects at 352 nm further supported the 3S,6S configuration of 1. Therefore, 1 was identified as (ϩ)-(3S,6S,7R,8S)-periconone A as shown in Fig.…”