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4α,5α-epoxyandrostan-17β-yl acetate is a chemical with a specific purpose. Lookchem provides you with multiple data and supplier information of this chemical.

168254-08-8

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168254-08-8 Usage

Check Digit Verification of cas no

The CAS Registry Mumber 168254-08-8 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 1,6,8,2,5 and 4 respectively; the second part has 2 digits, 0 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 168254-08:
(8*1)+(7*6)+(6*8)+(5*2)+(4*5)+(3*4)+(2*0)+(1*8)=148
148 % 10 = 8
So 168254-08-8 is a valid CAS Registry Number.

168254-08-8Upstream product

168254-08-8Relevant academic research and scientific papers

Oxidation of Δ4- and δ5-steroids with hydrogen peroxide catalyzed by porphyrin complexes of MnIII and FeIII

Rebelo, Susana L. H.,Simoes, Mario M. Q.,M. Graca P. M. S. Neves,Silva, Artur M. S.,Cavaleiro, Jose A. S.,Peixoto, Andreia F.,Pereira, Mariette M.,Silva, Manuela R.,Paixao, Jose A.,Beja, Ana M.

, p. 4778 - 4787 (2004)

In this paper we describe a new environmentally friendly method to promote the stereoselective epoxidation of Δ4- and Δ5- steroids. Metalloporphyrins efficiently catalyze the epoxidation reactions of 17β-acetoxy-4-androstene (1), 4-cholestene (2) and 3β-acetoxy-5- cholestene (3) in the presence of H2O2 as oxygen donor. Modeling the molecular structure of the porphyrin as well as the central metal allows the control of the preferential formation of α- or β-epoxides. Porphyrins with bulky, electron-withdrawing groups in the ortho positions of the meso phenyls and with MnIII as the central metal ion, such as [Mn(TDCPP)Cl], gave preferentially the β-epoxide of Δ4- and Δ5-steroids. [Fe(TPFPP)Cl] catalyzes preferentially the α-epoxidation of Δ4-steroids and also increases the stereoselectivity for the α-epoxide in Δ5-steroids, similar to the results obtained with m-CPBA (m-chloroperbenzoic acid) as oxidant. The substrate structure strongly influences the chemoselectivity of the reactions. The X-ray structures of two main products were determined, and two-dimensional NMR techniques allowed the full assignment of 1H and 13C NMR resonances as well as the stereochemistry of these products. A mechanistic proposal involving oxo species for the β-approach and peroxy species for the α-approach is proposed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

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