61574-54-7Relevant academic research and scientific papers
Regioselective Synthesis Using the Deuterium Isotope Effect
Miyano, Masateru
, p. 1854 - 1857 (1981)
Dehydration of 1a by various procedures invariably produced more exo olefin 2a than endo olefin 3a.This could be reversed by introduction of deuterium in the Me-21 group of the starting material.Thus, dehydration of 1b could afford more endo olefin 3b than exo olefin 2b due to the deuterium isotope effect.A regioselective synthesis of 18-oxoprogesterone (15a) from 3β-hydroxypregn-5-en-20-one (5a) was carried out taking advantage of the deuterium isotope effect as depicted in Scheme I.The key steps were dehydration of 7b to predominantly endo olefin 9b and removalof the deuteriums from 18-oxoprogesterone-17α,21,21,21-d4 (15b) to give 15a.
Spontaneous conversion of prenyl halides to acids: application in metal-free preparation of deuterated compounds under mild conditions
Darshana, Dhanushka,Sureram, Sanya,Mahidol, Chulabhorn,Ruchirawat, Somsak,Kittakoop, Prasat
supporting information, p. 7390 - 7402 (2021/09/07)
Here we reveal a simple generation of deuterium halide (DX) from common and inexpensive reagents readily available in a synthetic chemistry laboratory,i.e. prenyl-, allyl-, and propargyl halides, under mild conditions. We envisaged thatin situgeneration of an acid, deuterium halide, would be useful for acid-catalyzed reactions and could be employed for organocatalytic deuteration. The present work reports a metal-free method for deuterium labeling covering a broad range of substrate including phenolic compounds (i.e. flavonoids and stilbenes), indoles, pyrroles, carbonyl compounds, and steroids. This method was also applied for commonly used drugs such as loxoprofen, haloperidol, stanolone, progesterone, androstenedione, donepezil, ketorolac, adrenosterone, cortisone, pregnenolone, and dexamethasone. A gram-scale chromatography-free synthesis of some deuterated compounds is demonstrated in this work. This work provides a simple, clean and by-product-free, site-selective deuteration, and the deuterated products are obtained without chromatographic separation. When applying these initiators for other acid-catalyzed reactions, the deuterium isotope effects of DX may provide products which are different from those obtained from reactions using common acids. Although the mechanism of the spontaneous transformation of prenyl halides to acid is unclear, this overlooked chemistry may be useful for many reactions.
Isotope-Labeling Studies Support the Electrophilic Compound i Iron Active Species, FeO3+, for the Carbon-Carbon Bond Cleavage Reaction of the Cholesterol Side-Chain Cleavage Enzyme, Cytochrome P450 11A1
Yoshimoto, Francis K.,Jung, I-Ji,Goyal, Sandeep,Gonzalez, Eric,Guengerich, F. Peter
, p. 12124 - 12141 (2016/10/03)
The enzyme cytochrome P450 11A1 cleaves the C20-C22 carbon-carbon bond of cholesterol to form pregnenolone, the first 21-carbon precursor of all steroid hormones. Various reaction mechanisms are possible for the carbon-carbon bond cleavage step of P450 11A1, and most current proposals involve the oxoferryl active species, Compound I (FeO3+). Compound I can either (i) abstract an O-H hydrogen atom or (ii) be attacked by a nucleophilic hydroxy group of its substrate, 20R,22R-dihydroxycholesterol. The mechanism of this carbon-carbon bond cleavage step was tested using 18O-labeled molecular oxygen and purified P450 11A1. P450 11A1 was incubated with 20R,22R-dihydroxycholesterol in the presence of molecular oxygen (18O2), and coupled assays were used to trap the labile 18O atoms in the enzymatic products (i.e., isocaproaldehyde and pregnenolone). The resulting products were derivatized and the 18O content was analyzed by high-resolution mass spectrometry. P450 11A1 showed no incorporation of an 18O atom into either of its carbon-carbon bond cleavage products, pregnenolone and isocaproaldehyde. The positive control experiments established retention of the carbonyl oxygens in the enzymatic products during the trapping and derivatization processes. These results reveal a mechanism involving an electrophilic Compound I species that reacts with nucleophilic hydroxy groups in the 20R,22R-dihydroxycholesterol intermediate of the P450 11A1 reaction to produce the key steroid pregnenolone.
Incorporation of Label from 18O2 into Acetate during Side-chain Cleavage Catalysed by Cytochrome P-45017α (17α-hydroxylase-17,20-lyase)
Akhtar, Muhammad,Corina, David L.,Miller, Sharon L.,Shyadehi, Akbar Z.,Wright, J. Neville
, p. 263 - 268 (2007/10/02)
Samples of pregnenolone and 17α-hydroxypregnenolone deuteriated at the C-21 methyl group have been prepared and subjected to side-chain cleavage with a pig tested microsomal preparation under 18O2. 17α-Hydroxypregnenolone was exclusively cleaved to dehydroisoandrosterone and the acetic acid released during the process was found to incorporate 0.90 atom of 18O.When a similar incubation was performed with pregnenolone two steroidal products, dehydroisoandrosterone and androsta-5,16-dien-3β-ol, were formed in an approximate ratio of 1:2-3 and the acetic acid formed in the process was again shown to contain 0.85 - 0.90 atom of 18O.Complementary experiments in which the two substrates labelled with 18O at the C-20 carbonyl group were incubated under 16O2 gave acetic acid retaining between 65 - 85percent of the original carbonyl oxygen.The experiments strengthen the hypothesis that the two C(17) - C(20) bond cleavages described above correspond to the acyl-carbon fission process of the equation below showing the indicated fate of the various oxygen atoms:
