- Analysis of testosterone and dehydroepiandrosterone in saliva by gas chromatography-mass spectrometry
-
Testosterone and 3β-hydroxyandrost-5-en-17-one (dehydroepiandrosterone) have been identified in human parotid fluid and saliva by gas chromatography-mass spectrometry/selected ion monitoring analyses of the t-butyldimethylsilyl ether and methyl oxime, t-butyldimethylsilyl ether derivatives. High specificity of analysis has been achieved by the use of high mass spectrometric resolution or by the monitoring of metastable peaks. Quantitative analyses indicate concentrations of both unconjugated testosterone and unconjugated dehydroepiandrosterone in the range 200-800 pmol/l in the saliva and parotid fluid of the normal males examined. These represent 1.5-7.5% of the concentrations of the steroids in blood plasma taken from the same subjects.
- Gaskell,Pike,Griffiths
-
-
Read Online
- Chemical synthesis of 7-oxygenated 12α-hydroxy steroid derivatives to enable the biochemical characterization of cytochrome P450 8B1, the oxysterol 12α-hydroxylase enzyme implicated in cardiovascular health and obesity
-
Cholic acid is the endogenous 12α-hydroxylated bile acid, which possesses enhanced cholesterol absorption properties compared to its 12-desoxy counterpart, chenodeoxycholic acid. The oxysterol 12α-hydroxylase enzyme is cytochrome P450 8B1 (P450 8B1), which regioselectively and stereoselectively incorporates the 12α-hydroxy group in 7α-hydroxycholest-4-en-3-one, the biosynthetic precursor of cholic acid. Despite the vital role of P450 8B1 activity in cardiovascular health, research studies of other 12α-hydroxy steroid derivatives are rare. A synthetic route to incorporate a C12α-hydroxy group into the C12-methylene (–CH2–) in dehydroepiandrosterone derivatives is disclosed. The incorporation of the C12-oxygen was accomplished through a copper mediated Sch?necker oxidation of an imino-pyridine intermediate, introducing the 12β-hydroxy group. The resulting 12β-hydroxy steroid derivative was oxidized to the C12-ketone, which was stereoselectively reduced with lithium tri-sec-butylborohydride to afford the 12α-hydroxy stereochemistry. The C7-position was oxidized to yield the various 7-keto, 7β-hydroxy, and 7α-hydroxy derivatives. Furthermore, 7-ketodehydroepiandrosterone and 12 α-hydroxy-7-ketodehydroepiandrosterone both displayed NMDA receptor antagonistic activities at 10 μM concentrations. These C12α-hydroxy steroids will be used as tools to identify new biochemical properties of the enzymatic products of P450 8B1, the oxysterol 12α-hydroxylase.
- Offei, Samuel D.,Arman, Hadi D.,Baig, Mirza Oais,Chavez, Lazaro S.,Paladini, Carlos A.,Yoshimoto, Francis K.
-
-
Read Online
- Novel steroidal vinyl fluorides as inhibitors of steroid C17(20) lyase
-
20-Fluoro-17(20)-pregnenolone derivatives were designed as enol mimics of pregnenolone. All of the targeted, novel fluoroolefins were potent inhibitors of C17(20) lyase. Copyright
- Burkhart, Joseph P,Weintraub, Philip M,Gates, Cynthia A,Resvick, Robert J,Vaz, Roy J,Friedrich, Dirk,Angelastro, Michael R,Bey, Philippe,Peet, Norton P
-
-
Read Online
- Photooxygenation of pregnanes
-
The course of the singlet-oxygen reaction with pregn-17(20)-enes and pregn-5,17(20)-dienes was studied to compare the reactivity of the two alkene moieties present in some steroid families. Thus, from commercially available (3β,5α)-hydroxy-androstan-17-one and (3β)-3-hydroxyandroxst-5- en-17-one, the following 3-{[(tertbutyl)dimethylsilyl]oxy}-substituted, 17(20)-unsaturated pregnanes were prepared (see Fig. 1): (3β,5α)-21- norpregn-17(20)-ene 1; (3β,5α,17Z)-pregn-17(20)-ene 2, (3β,5α,16α,17E)-pregn-17(20)-en-16-ol 3, (16β,5α, 17E-pregn-17(20)-en-16-ol 4, (3β,5α,16β,17E)-pregn-17(20)-en-16- ol acetate 5, (3β,16α)-21-norpregna-5,17(20)-dien-16-ol 6, (3β,16α,17E)-pregna-5,17(20)-dien-16-ol 7, (3β,17Z)-pregna-5, 17(20)-diene 8, (3β,17E)-pregna-5,17(20)-dien-21-ol 9 and (3β,17E)-5,17(20)-dien-21-ol acetate 10. The oxygenated products (see Fig. 2) obtained from 1-10 and 1O2, generated by irradiation of Rose Bengal in 3O2-saturated pyridine solution, were characterized by 1H-, 13C-NMR, and MS (EI, FAB, HR-EI, ESI- and UV-MALDI-TOF) data. Major products were those formed by the ene reaction involving as intermediates the corresponding hydroperoxides and the cyclic tautomers of the allylic hydroperoxides, i.e., the corresponding oxiranium oxide-like intermediate (Scheme 5).
- Ponce, Maria A.,Erra-Balsells, Rosa,Bruttomesso, Andrea C.,Gros, Eduarde G.
-
-
Read Online
- Inhibition of steroid C(17(20)) lyase with C-17-heteroaryl steroids
-
Steroids bearing a heteroaromatic substituent at C-17 were designed as inhibitors of C(17(20)) lyase. The thiazoles, furans, and thiophenes appended to the steroid nucleus were positioned on the α-face and the β-face of the steroid, and conjugated with a 16,17-olefin, to test their ability to coordinate the heme iron of the P450 enzyme complex. The position of the heterocycle with respect to the steroid skeleton was determined to be important for optimum affinity and, in general, compounds with the heterocycle attached to a trigonal center at C-17, had the best affinity for C(17(20)) lyase. Simple molecular models were used to compare the three types of heterocyclic-substituted steroids.
- Burkhart, Joseph P.,Gates, Cynthia A.,Laughlin, Marie E.,Resvick, Robert J.,Peet, Norton P.
-
-
Read Online
- Highly Efficient Nucleophilic Addition of Alkyl Grignard Reagents to 17-Ketosteroids in the Presence of Cerium(III)Chloride: Synthesis of 17α-Propyl-17β-Hydroxy-4-Androsten-3-one, An Androgen Receptor Antagonist
-
The addition of alkyl Grignard reagents to sterically hindered 17-ketosteroids was significantly enhanced by anhydrous cerium(III) chloride with notable suppression of abnormal reactions, while the addition products were obtained in good to excellent yields and high stereoselectivity.
- Li, Xun,Singh, Shankar M.,Labrie, Fernand
-
-
Read Online
- Structure-activity relationship and mechanistic study on guggulsterone derivatives; Discovery of new anti-pancreatic cancer candidate
-
Pancreatic cancer is one of the deadliest types of malignancies. A new intervention aiming to combat pancreatic cancer is targeting its extra-ordinary ability to tolerate nutrition starvation, a phenomenon known as “Austerity”. As a part of a research program aiming to develop a new-generation of anticancer agents, known as “anti-austerity agents”, guggulsterone derivatives (GSDs) were identified as unique anti-austerity agents in terms of potency and selectivity. These agents are able to exert preferential cytotoxic activity only under nutrient-deprived conditions with little or no toxicity under normal conditions. In the present study, a library of 14 GSDs was synthesized and screened against PANC-1 human pancreatic cells. Among tested compounds, GSD-11 showed the most potent activity with PC50 a value of 0.72 μM. It also inhibited pancreatic cancer cell migration and colony formation in a concentration-dependent manner. A mechanistic study revealed that this compound can inhibit the activation of the Akt/mTOR signaling pathway. Therefore, GSD-11 could be a promising lead compound for the anticancer drug discovery against pancreatic cancer.
- Kohyama, Aki,Kim, Min Jo,Yokoyama, Rei,Sun, Sijia,Omar, Ashraf M.,Phan, Nguyen Duy,Meselhy, Meselhy R.,Tsuge, Kiyoshi,Awale, Suresh,Matsuya, Yuji
-
supporting information
(2021/12/24)
-
- Design, Synthesis, and Study of the Insecticidal Activity of Novel Steroidal 1,3,4-Oxadiazoles
-
A series of novel steroidal derivatives with a substituted 1,3,4-oxadiazole structure was designed and synthesized, and the target compounds were evaluated for their insecticidal activity against five aphid species. Most of the tested compounds exhibited potent insecticidal activity against Eriosoma lanigerum (Hausmann), Myzus persicae, and Aphis citricola. Compounds 20g and 24g displayed the highest activity against E. lanigerum, showing LC50 values of 27.6 and 30.4 μg/mL, respectively. Ultrastructural changes in the midgut cells of E. lanigerum were detected by transmission electron microscopy, indicating that these steroidal oxazole derivatives might exert their insecticidal activity by destroying the mitochondria and nuclear membranes in insect midgut cells. Furthermore, a field trial showed that compound 20g exhibited effects similar to those of the positive controls chlorpyrifos and thiamethoxam against E. lanigerum, reaching a control rate of 89.5% at a dose of 200 μg/mL after 21 days. We also investigated the hydrolysis and metabolism of the target compounds in E. lanigerum by assaying the activities of three insecticide-detoxifying enzymes. Compound 20g at 50 μg/mL exhibited inhibitory action on carboxylesterase similar to the known inhibitor triphenyl phosphate. The above results demonstrate the potential of these steroidal oxazole derivatives to be developed as novel pesticides.
- Bai, Hangyu,Jiang, Weiqi,Li, Qi,Li, Tian,Ma, Shichuang,Shi, Baojun,Wu, Wenjun
-
p. 11572 - 11581
(2021/10/12)
-
- Chemo- and Enantioselective Oxidative α-Azidation of Carbonyl Compounds
-
We report high-performance I+/H2O2 catalysis for the oxidative or decarboxylative oxidative α-azidation of carbonyl compounds by using sodium azide under biphasic neutral phase-transfer conditions. To induce higher reactivity especially for the α-azidation of 1,3-dicarbonyl compounds, we designed a structurally compact isoindoline-derived quaternary ammonium iodide catalyst bearing electron-withdrawing groups. The nonproductive decomposition pathways of I+/H2O2 catalysis could be suppressed by the use of a catalytic amount of a radical-trapping agent. This oxidative coupling tolerates a variety of functional groups and could be readily applied to the late-stage α-azidation of structurally diverse complex molecules. Moreover, we achieved the enantioselective α-azidation of 1,3-dicarbonyl compounds as the first successful example of enantioselective intermolecular oxidative coupling with a chiral hypoiodite catalyst.
- Hattori, Yuhei,Ishihara, Kazuaki,Sahara, Naoto,Tsukahara, Mayuko,Uyanik, Muhammet
-
supporting information
p. 17110 - 17117
(2020/08/10)
-
- Synthesis and biological evaluation of analogs of didehydroepiandrosterone as potential new anticancer agents
-
The synthesis, cytotoxicity and inhibition of CDK8 by thirteen analogs of cortistatin A are reported. These efforts revealed that the analogs with either a 6- or 7-isoquinoline or 5-indole side chain in the 17-position are the most promising anti-proliferative agents. These compounds showed potent cytotoxic effects in CEM, HeLa and HMEC-1 cells. All three compounds exhibited IC50 values 10μM. The most interesting 10l analog exhibited an IC50 value of 0.59 μM towards the human dermal microvascular endothelial cell line (HMEC-1), significantly lower than the reference standard 2-methoxyestradiol. At a concentration at 50 nM the most potent 10h compound reduced the activity of CDK8 to 35percent.
- Hansen, Trond Vidar,Liekens, Sandra,Solu, Eirik J.
-
supporting information
(2020/07/30)
-
- ENZYME COMPOSITIONS, STEROID DERIVATIVES, ENZYME INHIBITORS, AND METHODS OF MAKING SAME FOR PHARMACEUTICAL APPLICATIONS
-
The present disclosure provides for a synthetic strategy to incorporate a C12α-hydroxy group from the methylene (—CH2-) in a steroid backbone, combining synthetic chemistry and enzymology techniques to develop a selective inhibitor for cytochrome P450 8B1, and developing a selective P450 8B1 inhibitor, which can be used as a tool to study P450 8B1 and treat health issues.
- -
-
Paragraph 0135
(2020/06/29)
-
- Electro-Olefination—A Catalyst Free Stereoconvergent Strategy for the Functionalization of Alkenes
-
Conventional methods carrying out C(sp2)?C(sp2) bond formations are typically mediated by transition-metal-based catalysts. Herein, we conceptualize a complementary avenue to access such bonds by exploiting the potential of electrochemistry in combination with organoboron chemistry. We demonstrate a transition metal catalyst-free electrocoupling between (hetero)aryls and alkenes through readily available alkenyl-tri(hetero)aryl borate salts (ATBs) in a stereoconvergent fashion. This unprecedented transformation was investigated theoretically and experimentally and led to a library of functionalized alkenes. The concept was then carried further and applied to the synthesis of the natural product pinosylvin and the derivatization of the steroidal dehydroepiandrosterone (DHEA) scaffold.
- Baumann, Andreas N.,Dechent, Jonas,Didier, Dorian,Jagau, Thomas C.,Müller, Nicolas,Music, Arif
-
supporting information
(2020/07/04)
-
- Synthesis and antitumor activity of novel steroidal imidazolium salt derivatives
-
Sixty-one novel steroidal imidazolium salt derivatives were synthesized and evaluated in vitro against a panel of human tumor cell lines. The results showed that diosgenin?imidazolium salt derivatives displayed much higher cytotoxic activities than choles
- Deng, Guogang,Zhou, Bei,Wang, Jing,Chen, Zhuo,Gong, Liang,Gong, Yaxiao,Wu, Dongmei,Li, Yan,Zhang, Hongbin,Yang, Xiaodong
-
supporting information
p. 232 - 252
(2019/02/28)
-
- 17 beta-imidazolidinyl bromide-dehydroepiandrostane derivative and preparation method and application thereof
-
The invention provides a 17 beta- imidazolidinyl bromide-dehydroepiandrostane derivative which has the good pharmacological activity and can be applied to preparation of anti-tumor drugs. Based on theembodiment result, the obtained 17 beta-imidazolidinyl
- -
-
Paragraph 0109; 0110
(2019/01/14)
-
- Synthesis and biological evaluation of novel steroidal 5α,8α-endoperoxide derivatives with aliphatic side-chain as potential anticancer agents
-
By inspiration of significant anti-cancer activity of our previously screened natural ergosterol peroxide (EP), a series of novel steroidal 5α,8α-endoperoxide derivatives 5a–d and 14a–f were designed, synthesized, and biologically evaluated for their in vitro anti-proliferative inhibitory and cytotoxic activity. The results revealed that most of these compounds showed moderate-to-excellent anti-proliferative effects against the tested cancer cell lines (i.e. HepG2, SK-Hep1, MDA-MB-231 and MCF-7). Among them, compound 5b and 14d exhibited preferable inhibitory activities (IC50 of 5b and 14d are 8.07 and 9.50?μM against HepG2, respectively). The structure-activity relationships indicated that incorporation the peroxidic bridge to the steroid scaffolds at C-5 and C-8 positions together with the aliphatic side-chain at the C-17 position would provide synergistic effect for the bioactivity.
- Bu, Ming,Cao, Tingting,Li, Hongxia,Guo, Mingzhou,Yang, Burton B.,Zhou, Yue,Zhang, Na,Zeng, Chengchu,Hu, Liming
-
-
- A method for avoiding heavy metal residual acetate preparation method
-
The invention discloses a novel method for preparing abiraterone acetate. The method comprises the following steps of: hydroxyl protection, Aldol reaction, dehydration reaction, deprotection and acetylation. According to the method, the heavy-metal reagent, the strict anhydrous and anaerobic equipment and the expensive alkyl boron reagent are not used, thus the cost is reduced greatly. The method is suitable for mass industrial production.
- -
-
Paragraph 0017; 0077; 0078; 0079; 0080
(2017/08/25)
-
- C?H Acetoxylation-Based Chemical Synthesis of 17 β-Hydroxymethyl-17 α-methyl-18-norandrost-13-ene Steroids
-
Palladium-catalyzed C?H acetoxylation has been proposed as a key transformation in the first chemical synthesis of steroids bearing a unique 17β-hydroxymethyl-17α-methyl-18-nor-13-ene D-fragment. This C?H functionalization step was crucial for inverting the configuration at the quaternary stereocenter of a readily available synthetic intermediate. The developed approach was applied to prepare the metandienone metabolite needed as a reference substance in anti-doping analysis to control the abuse of this androgenic anabolic steroid.
- Hurski, Alaksiej L.,Barysevich, Maryia V.,Dalidovich, Tatsiana S.,Iskryk, Marharyta V.,Kolasava, Nastassia U.,Zhabinskii, Vladimir N.,Khripach, Vladimir A.
-
supporting information
p. 14171 - 14174
(2016/09/23)
-
- Novel nor-homo-and spiro-oxetan- steroids target the human androgen receptor and act as antiandrogens
-
The prostate adenocarcinoma is the cancer with the highest incidence for men in Western countries. Targeting the androgen receptor (AR) by antagonists is used as hormone therapy for prostate cancer (PCa), however, eventually therapy resistance occurs in most patients. In most of these cancer the AR signaling is active and thus AR remains an important drug target. Since many years we are characterizing novel chemical structural platforms to provide a broader possibility for compounds that bind to and act as AR antagonists. Here, we describe the chemical synthesis of a battery of novel steroidal derivatives as nor-homo-, spiro-oxolan- and spiro-oxetan- steroids. They modulate the transcriptional activity of the human AR. As AR antagonists, the spiro-oxetan- steroid derivatives seem to be the most potent steroid derivatives. They inhibit the transcriptional activity of both wild-type AR as well as the AR mutant T877A. In line with this, these compounds bind to the human AR and inhibit the proliferation of the human androgen-dependent growing PCa cell line LNCaP. Interestingly, the castration-resistant AR expressing human PC3-AR cells are also growth inhibited. On mechanistic level, fluorescence resonance energy transfer (FRET) assays with living cells indicate that the androgeninduced N/C terminal interaction of the AR is inhibited by the investigated compounds. Using fluorescence recovery after photobleaching (FRAP) assays in living cells suggest a higher mobility of the AR in the cell nuclei in the presence of spiro-oxetan- steroidal antagonists. Together, these findings suggest that spiro-oxetan- steroids are very useful as a chemical platform for novel AR antagonists.
- Thiele,Rabe,Hessenkemper,Roell,Bartsch,Kraft,Abraham,Houtsmuller,Van Royen,Giannis,Baniahmad
-
p. 1156 - 1167
(2015/06/22)
-
- PROCESS FOR THE PREPARATION OF ABIRATERONE AND INTERMEDIATES THEREOF
-
The present invention provides intermediates for preparing abiraterone, and processes for preparing abiraterone and intermediates thereof. The intermediates include a compound of formula (IV): wherein R represents a hydroxy-protecting group.
- -
-
Paragraph 0110; 0111
(2015/02/05)
-
- SYNTHESIS OF ABIRATERONE AND RELATED COMPOUNDS
-
The present invention relates to processes for obtaining abiraterone and derivatives thereof, such as abiraterone acetate, by means of a Suzuki coupling through a steroid borate of general formula (IV) or a C—C coupling through a steroid hydrazone of general formula (II), as well as to intermediates useful in said processes.
- -
-
Paragraph 0233; 0234; 0235; 0236; 0237
(2014/02/15)
-
- PROCESS AND INTERMEDIATES FOR THE PREPARATION OF ABIRATERONE ACETATE
-
The present invention relates to a process for the synthesis of (3beta)17-(3- pyridinyl)androsta-5,16-dien-3-yl acetate (Abiraterone acetate) represented by the structure of formula (1), and salts thereof, especially salts with pharmaceutically acceptable acids. The present invention further relates to certain intermediates in such processes.
- -
-
Page/Page column 23; 24
(2014/02/16)
-
- SYNTHESIS OF ABIRATERONE AND RELATED COMPOUNDS
-
The present invention relates to processesfor obtaining abirateroneand derivatives thereof, such as abiraterone acetate, by means of a Suzuki coupling through a steroid borate of general formula (IV) or a C-C coupling through a steroid hydrazone of general formula (II), as well as to intermediates useful in said processes.
- -
-
Page/Page column 38
(2013/03/28)
-
- Processes for the preparation of abiraterone and related compouds
-
The present invention relates to processes for obtaining abiraterone and derivatives thereof, such as abiraterone acetate, by means of a C-C coupling through a steroid hydrazone of general formula (II) or a Suzuki coupling through a steroid borate of general formula (IV), as well as to intermediates useful in said processes.
- -
-
Paragraph 0120; 0121; 0122; 0123; 0124
(2013/07/19)
-
- Synthesis of 1-deoxymaxacalcitol
-
1-Deoxymaxacalcitol, the 1-deoxygenated derivative of maxacalcitol practically used for the treatment of secondary hyperparathyroidism and psoriasis, has been synthesized for the biological evaluation. Although purification of the key intermediate contain
- Yamauchi, Tsuyoshi,Kato, Masahiro,Mikami, Tetsuhiro,Fujimura, Yasuo
-
p. 2107 - 2118
(2007/10/03)
-
- Total synthesis of the anticancer natural product OSW-1
-
The highly potent anticancer natural saponin OSW-1 has been successfully synthesized from commercially available 5-androsten-3β-ol-17-one 79 in 10 operations with 28% overall yield. The key steps in the total synthesis included a highly regio- and stereoselective selenium dioxide-mediated allylic oxidation of 80 and a highly stereoselective 1,4-addition of α-alkoxy vinyl cuprates 68 to steroid 17(20)-en-16-one 12E to introduce the steroid side chain. This total synthesis demonstrated once again the versatile synthetic applications of α-halo vinyl ether chemistry developed in our laboratories.
- Yu, Wensheng,Jin, Zhendong
-
p. 6576 - 6583
(2007/10/03)
-
- ++16 unsaturated C17 heterocyclic steroids useful as steroid C17-20 lyase inhibitors
-
The present invention relates to Δ16 unsaturated steroids which are useful as steroid C17-20 lyase inhibitors.
- -
-
-
- 16 unsaturated C17 heterocyclic steroids useful as steroid C17-20 lyase inhibitors
-
The present invention relates to Δ16 unsaturated C17 heterocyclic steroids which are useful as steroid C17-20 lyase inhibitors.
- -
-
-
- 22-oxacholecalciferol derivative and process for preparing the same
-
A 22-oxacholecalciferol derivative represented by formula (I): STR1 wherein R1 represents a hydrogen atom or a hydroxyl group; and R2 and R3, which may be the same or different, each represent a lower alkyl group having fr
- -
-
-
- A Facile Method to Append Peptidal Side-Chains onto Steroidal Templates
-
Side-Chains corresponding to phenylalanine, tyrosine and tryptophan are introduced onto a steroid template in a highly efficient manner via a condensation of the appropriate lithium acetylide with a steroidal ketone.The subsequent acetylene functionality can be selectively reduced in the presence of a modified benzyl ether and steroid ring unsaturation.
- Horwell, David C.,Lennon, Ian C.,Roberts, Edward
-
p. 4225 - 4234
(2007/10/02)
-
- PREPARATION OF 6-AZAANDROST-4-ENE-3,7,17-TRIONE AND SOME RELATED 3-OXYGENATED 6-AZAANDROSTANES
-
The synthesis of 6-azaandrost-4-ene-3,7,17-trione and of several related 3-oxygenated 6-azaandrostanes was achieved from 3β-hydroxyandrost-5-en-17-one.
- Back, Thomas G.,Baron, Denise L.,Morzycki, Jacek W.
-
p. 1053 - 1060
(2007/10/02)
-
- On the stability and radical deoxygenation of tertiary xanthates
-
Xanthates of tertiary alcohols were isolated and properly characterized. Radical deoxygenation reactions under various conditions to the corresponding alkanes were successfully carried out. Comparative data of various initiators and hydrogen atom donors for xanthate deoxygenation are reported.
- Barton,Parekh,Tse
-
p. 2733 - 2736
(2007/10/02)
-
- A New Stereoselective Synthesis of (20R)- and (20S)-Steroidal Side Chains
-
Reaction of (E)-ethyl 3β-t-butyldimethylsiloxypregna-5,17-dien-21-oate with lithium di-isopropylamide followed by alkyl halides results in the predominant formation of (20S)-alkylation products in >88percent isolated yields; a synthetic application to both (20R)- and (20S)-steroidal side chains is also described.
- Ibuka, Toshiro,Taga, Tooru,Nishii, Shinji,Yamamoto, Yoshinori
-
p. 342 - 344
(2007/10/02)
-
- Synthetic Approaches to the Ring System of Nicandra (Benzenoid Ring D) Steroids
-
The androstenolone derivative (5) has been converted into the aromatic ring D steroid (39), with the C/D system of the novel natural steroid Nic-10.The route employs the seco-acid (15) which is cyclised to the D-enone (16).Selective D-aromatisation was en
- Blumbach, J.,Hammond, D. A.,Whiting, D. A.
-
p. 261 - 268
(2007/10/02)
-
- Regio- and stereoselective introduction of 15β-hydroxy group and side chains to steroids by the palladium-catalyzed reaction of 1,3-diene monoepoxide
-
The Pd-catalyzed reaction of 1,3-diene monoepoxides with carbonucleophiles is applied to the regio- and stereoselective introduction of 15β-hydroxy group and side chains to steroid nuclei. 3β-Hydroxyandrost-5-en-17-one (15) was converted to 15,16β-epoxy-Δ17(20) isoheptylidene steroid 20 and ethylidene steroid 21. The former was subjected to the Pd-catalyzed reaction with dimethyl malonate and then converted to 15β-hydroxycholesterol (29). Similarly, 15β-hydroxyisocholesterol (32) was obtained from the ethylidene steroid 21 using the Pd-catalyzed reaction of methyl 3-oxo-5-methylhexanoate (24) as a key reaction.
- Takahashi, Takashi,Ootake, Atsushi,Tsuji, Jiro,Tachibana, Kazuo
-
p. 5747 - 5754
(2007/10/02)
-
- Pyridinium Fluorochromate or benzyltrimethylammonium Chlorochromate for selective Oxidation of Alcohols.
-
Selective oxidation of secondary alcohols in the presence of primary ones has been achieved by the following sequences, (1) selective protection of primary alcohols with t-BuMe2SiCl, (2) oxidation of secondary alcohols with title reagents, and (3) deprotection of primary hydroxyls.
- Nonaka, Tsuyoshi,Kanemoto, Shigekazu,Oshima, Koichiro,Nozaki, Hitosi
-
p. 2019 - 2020
(2007/10/02)
-
- Identification and quantification of dehydroepiandrosterone sulphate in saliva
-
3β-Hydroxy-5-androsten-17-one (dehydroepiandrosterone) sulphate has been separated from an extract of human saliva by ion exchange gel chromatography and identified by high resolution gas chromatography-high resolution mass spectrometry of the tert-butyldimethylsilyl derivative of the neutral steroid obtained by enzymic hydrolysis. Quantitative analyses, employing 7,7-2H-dehydroepiandrosterone sulphate as the internal standard, have indicated concentrations in the saliva of young adult subjects to be generally in the range 0.9-5.7 nmol/l, though concentrations as high as 10.7 nmol/l have been observed.
- Finlay,Morton,Gaskell
-
-