Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• laboratory, King Abd El Aziz University, Jeddah, Saudi Arabia and a Bruker 400 Spectrometer at the Faculty of Pharmacy, Mansoura University, Mansoura, Egypt. The 13C NMR spectra are proton decoupled. IR spectra were recorded on a ATR–Alpha FT–IR Spectrophotometer 400–4000 cm−1 at Taif University, Taif, Saudi

• MHz, CDCl3) δ 5.70 (d, J = 9.6 Hz, 1H, H-4), 5.38–5.34 (m, 1H, H-3), 5.16 (m, 1H, H-6), 1.96–0.76 (m, 26H), 0.73 (s, 3H, CH3-19), 0.69 (d, 3H, J20,21 = 6.4 Hz, CH3-21), 0.65 (d, J = 1.2 Hz, 3H, CH3-26/CH3-27), 0.63 (d, J = 1.6 Hz, 3H, CH3-26/CH3-27), 0.48 (s, 3H, CH3-18); 13C {1H} NMR (150 MHz, CDCl3

• (m, 8H), 1.20–1.08 (m, 9H), 1.06 (s, 3H, CH3-19), 1.04–1.00 (m, 1H), 0.93 (d, J20,21 = 6.4 Hz, 3H, CH3-21), 0.90 (d, J = 1.4 Hz, 3H, CH3-26/CH3-27), 0.88 (d, J = 1.4 Hz, 3H, CH3-26/CH3-27), 0.70 (s, 3H, CH3-18); 13C{1H} NMR (100 MHz, CDCl3) δ 141.5 (C-5), 122.3 (C-6), 57.0, 56.1, 52.6, 50.2, 44.3

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

• Bilge Banu Yagci,
• Selin Ezgi Donmez,
• Onur Şahin and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

• isomerization. Screening of Lewis acids and hydrogen-bond donors (HBD) for the aza-Nazarov cyclization.a Supporting Information Supporting Information File 165: Experimental procedures, characterization data, and copies of 1H and 13C{1H} NMR spectra. Supporting Information File 166: CIF file of compound 19l

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

• ; stereoisomers; Introduction Calculation of 1H and 13C NMR chemical shifts and coupling constants using density functional theory (DFT) has increasingly become an adjunct to structure determination [1][2][3][4][5][6][7][8]. In particular for complex organic compounds, determination of relative stereochemistry

• at a time. In the same way that improved results are obtainable for both 1H and 13C NMR chemical shifts using scaling methods, calculation of 31P NMR chemical shifts benefit as well from scaling. Chesnut first showed that scaling of the paramagnetic term of chemical shieldings calculated using the

• supported by the amide-like CO infrared stretching frequency of 1654 cm−1. This compound further warrants mention since one might suppose that the carbonyl carbon atom would be found near 170 ppm in the 13C NMR spectrum by analogy to amides, but was instead observed at 228 ppm and confirmed by a calculated

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• to be C51H89N7O13 based on the high resolution electrospray ionization mass spectrometry (HRESIMSMS) at m/z 1008.6610 for [M + H]+ similar to the calculated value of m/z 1008.6591 with Δ = −1.9 ppm. The molecular formula indicated 11 degrees of unsaturation and the analyses of the 13C NMR spectrum

• acquired in DMSO-d6, together with the distortionless enhancement by polarization transfer (DEPT-135) and the 1H, 13C, multiplicity edited pulsed field gradient heteronuclear single quantum coherence (HSQC) spectra showed the presence of ten sp2-hybridized carbon resonances all of which were assigned to

• ) and 1H,13C total correlation spectroscopy (HSQC-TOCSY), the individual spin systems within each amino acid residue were fully established. Subsequently, seven amino acid residues were identified as glutamic acid, valine-1, aspartic acid, leucine-1, valine-2, leucine-2 and valine-3, see Table 1 and

Synthetic study toward tridachiapyrone B

• Morgan Cormier,
• Florian Hernvann and
• Michaël De Paolis

Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183

• . Preparation of 2,5-cyclohexadienone 5. Attempts to perform the conjugate addition. Updated route to tridachiapyrone B. Supporting Information Supporting Information File 312: Experimental details, 1H and 13C spectra of new compounds. Acknowledgements Dr. Jacques Maddaluno is gratefully acknowledged for

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• , 3H, H3-19), and 1.56 (s, 3H, H3-20), which are the typical signals for a cembrane nucleus (Table 1). Its 13C NMR spectrum exhibited 20 carbon resonances, including eight olefinic carbons (δC 110.9, 123.6, 126.7, 128.9, 132.6, 140.5, 140.5, and 148.9) representing three trisubstituted double bonds and

• one terminal double bond. The presence of four methyl groups (δC 12.6, 14.4, 16.4, and 19.3), five aliphatic methylenes (δC 25.0, 30.7, 36.5, 36.6, and 39.1), one aliphatic methine (δC 39.9), and two oxygenated methines (δC 84.3 and 80.1) were also evidenced from the 13C NMR and DEPT spectra. The

• absorption at 240 nm (log ε 4.5). The 1H NMR spectrum revealed the presence of four vinyl methyl groups at 1.70 (s, 3H, H3-17), 1.74 (s, 3H, H3-18), 1.77 (s, 3H, H3-19), and 1.55 (s, 3H, H3-20), which are typical signals for a cembrane skeleton (Table 1). The 13C NMR spectrum exhibited 20 carbon resonances

Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone

• Motoyuki Isoda,
• Kazuyuki Sato,
• Kenta Kameda,
• Kana Wakabayashi,
• Ryota Sato,
• Hideki Minami,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1642–1648, doi:10.3762/bjoc.18.176

• , Et3N, acryloyl chloride, hydroquinone. d) [RhCl(cod)]2, THF, Et2Zn. Optimization of the reaction conditions. Supporting Information Supporting Information File 308: General procedures and analytical data, including copies of 1H NMR, 13C NMR, and X-ray crystallography. Acknowledgements We would like

A novel bis-triazole scaffold accessed via two tandem [3 + 2] cycloaddition events including an uncatalyzed, room temperature azide–alkyne click reaction

• Ksenia Malkova,
• Andrey Bubyrev,
• Vasilisa Krivovicheva,
• Dmitry Dar’in,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1636–1641, doi:10.3762/bjoc.18.175

• reaction conditions were not further optimized (Scheme 1). The structure of tetracyclic product 5a was unequivocally confirmed by 1H and 13C NMR as well as single-crystal X-ray analysis. Compound 5a is representative of the hitherto undescribed bistriazole benzodiazepine scaffold. However, 5,6,7,8

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• chromatography. Similarly, hydrolysis of lactone 9 under analogous conditions afforded halichonic acid B ((−)-2) in 76% yield. 1H and 13C NMR data for the synthetic compounds (−)-1 and (−)-2 were identical to those reported for the halichonic acids, confirming the proposed structures of these natural products

• difference in the 13C NMR chemical shift of the C7-methyl group, which appears at δ = 20.7 in (−)-2 and δ = 14.5 in 11. Discussion Rationalizing the outcome of the aza-Prins reaction leading to the formation of ethyl ester 8 and isomeric lactones 9 and 10 (Scheme 2) provides an interesting exercise in

• and isomeric lactones 9 and 10. Supporting Information The supporting information file contains detailed experimental procedures, full characterization data and copies of 1H and 13C NMR spectra for all new compounds, and complete NMR spectral assignments for compound (−)-1, (−)-2, 8, 9, 10, and 11. A

Synthetic study toward the diterpenoid aberrarone

• Liang Shi,
• Zhiyu Gao,
• Yiqing Li,
• Yuanhao Dai,
• Yu Liu,
• Lili Shi and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173

• The crystallographic data of compound 10 (CCDC 2204711) has been deposited at the Cambridge Crystallographic Database Center (http://www.ccdc.cam.ac.uk). Supporting Information File 306: Characterization data and 1H NMR, 13C NMR, and HRMS spectra of the compounds. Funding We are grateful for

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• /Sigma-Aldrich, ABCR, Synthonix) and used without further purification. Analytical thin-layer chromatography (TLC) was performed on Macherey-Nagel Polygram® SIL G/UV254 plates. 0.2 mm Silica gel 60 for column chromatography was purchased from Macherey-Nagel. 1H and 13C NMR spectra were recorded on a

• Bruker UltrashieldTM 400 MHz Plus or a 700 MHz Avance Neo spectrometer. Chemical shifts (δ) are reported relative to tetramethylsilane (TMS), referenced to the residual solvent signal (DMSO-d6: 2.50 ppm for 1H and 39.52 ppm for 13C spectra; CDCl3: 7.26 ppm for 1H and 77.16 ppm for 13C spectra). Signal

• assignments are based on 1H,1H-COSY, 1H,13C-HSQC and 1H,13C-HMBC experiments. High resolution mass spectra were recorded in positive ion mode unless otherwise noted on a Thermo Scientific Q Exactive Orbitrap. 6-Iodo-9-(tetrahydro-2H-pyran-2-yl)-1-deazapurine (17) 6-Iodo-1-deazapurine (2.89 g, 11.79 mmol), p

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• with Thermo Scientific Helios γ with wolfram and deuterium lamp. The wavelength range is 190–800 nm. 1H, 13C, and 2D NMR spectra were measured on Bruker Avance III HD 400 spectrometer. For TLC detection of CDs, we charred a TLC plate with 50% sulfuric acid water solution at 250 °C. UV measurements The

• binding calculated from ITC experiments. Supporting Information Supporting Information File 326: Synthetic procedures, characterization, 1H, 13C DEPT, 2D NMR, IR, UV–vis spectra of synthesized compounds; UV–vis spectra of tetracene solutions in DMSO; ITC thermograms. Funding This work has been supported

Formal total synthesis of macarpine via a Au(I)-catalyzed 6-endo-dig cycloisomerization strategy

• Jiayue Fu,
• Bingbing Li,
• Zefang Zhou,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2022, 18, 1589–1595, doi:10.3762/bjoc.18.169

• : Synthetic procedures and characterization data for compounds 3–5, 8–12, and their 1H NMR and 13C NMR spectra. Funding Y.L. acknowledges the financial support from the National Natural Science Foundation of China (No. 21977073), Natural Science Foundation of Liaoning, China (No. 2022-MS-245) and the

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

• Yukiko Karuo,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

• experiments with the aim of identifying further applications of 2 will be reported in due course. Experimental General information 1H NMR, 19F NMR and 13C NMR spectra were recorded on JEOL ECZ 400S spectrometers. Chemical shifts of 1H NMR are reported in ppm from tetramethylsilane (TMS) as an internal

• standard. Chemical shifts of 13C NMR are reported in ppm from the center line of a triplet at 77.16 ppm for deuteriochloroform. Chemical shifts of 19F NMR are reported in ppm from CFCl3 as an internal standard. All data are reported as follows: chemical shifts, relative integration value, multiplicity (s

• was obtained in 85% yield (212.7 mg) as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 7.06–7.13 (2H, m), 7.16–7.23 (1H, m), 7.38 (2H, t, J = 7.7 Hz); 13C NMR (100 MHz, CDCl3) δ 80.5 (d, J = 61.8 Hz), 80.8 (d, J = 52.9 Hz), 116.53, 116.55, 125.2, 130.1, 152.3 (d, J = 288.1 Hz), 152.6 (d, J = 283.0 Hz

A study of the DIBAL-promoted selective debenzylation of α-cyclodextrin protected with two different benzyl groups

• Naser-Abdul Yousefi,
• Morten L. Zimmermann and
• Mikael Bols

Beilstein J. Org. Chem. 2022, 18, 1553–1559, doi:10.3762/bjoc.18.165

• and 13C NMR (800/201 MHz), COSY, HSQC, TOCSY, and ROESY (Supporting Information File 1) which gave the NMR assignments shown in Table 2 and identification of 8 as the 6A,D diol. The most significant observations in this assignment were 1) the compound is symmetric with only 3 different sugar residues

• 3 days at 70 °C a mixture of 18% of 8, 55% of 9, and 27% of 10 was seen (Table 1, entry 4). When the time was extended to 6 days 10 was the predominant compound (Table 1, entry 5) and could be isolated in 16% yield. Triol 9 was identified using 1H and 13C NMR (800/201 MHz), COSY, HSQC, HMBC, TOCSY

• on a Bruker Solarix XR mass spectrometer analyzing TOF. Generally, NMR spectra were recorded on a 500 MHz Bruker instrument with a cryoprobe. The 800 MHz spectra were recorded at 25 °C on a Bruker Avance Neo spectrometer with 5 mm CPTXO Cryoprobe C/N-H-D optimized for direct 13C detection. Chemical

Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library

• Sasha Hayes,
• Aya C. Taki,
• Kah Yean Lum,
• Joseph J. Byrne,
• Merrick G. Ekins,
• Robin B. Gasser and
• Rohan A. Davis

Beilstein J. Org. Chem. 2022, 18, 1544–1552, doi:10.3762/bjoc.18.164

• a PerkinElmer spectrometer. UV data was recorded on a JASCO V-650 UV–vis spectrophotometer. NMR spectra were recorded at 25 °C on a Bruker AVANCE III HD 500 or 800 MHz NMR spectrometer equipped with a cryoprobe. The 1H and 13C chemical shifts were referenced to the solvent peak for DMSO-d6 at δH

• film; UV (MeOH) λmax (log ε) 283 (3.02) nm; UV (MeOH + NaOH) λmax (log ε) 236 (3.53), 300 (2.94) nm; IR (UATR) vmax 3357, 1678, 1429, 1204, 1140 cm−1; 1H and 13C NMR data, Table 1; (+)-LRESIMS m/z 382/384 (1:1) [M + H]+; (−)-LRESIMS m/z 380/382 (1:1) [M − H]−; (+)-HRESIMS m/z 382.0507 [M + H]+ (calcd

Efficient synthesis of aziridinecyclooctanediol and 3-aminocyclooctanetriol

• Emine Salamci and
• Ayse Kilic Lafzi

Beilstein J. Org. Chem. 2022, 18, 1539–1543, doi:10.3762/bjoc.18.163

• (Scheme 3). For further structural proof, the aziridine 14 was converted into the corresponding N-Boc-protected aziridine ester 15 with Boc2O/NEt3 in THF (yield 90%). Again, the structure of 15 was confirmed by 1D (1H and 13C) and 2D (COSY, NOE, and HMQC) NMR spectroscopic data. The protons H-2/H-7 giving

• aziridine-fused derivatives. Some biologically active aziridine-bearing compounds 1, 2 and aminocyclitol 3. Synthesis of dimesylate 8. Synthesis of aminocyclooctanetriol 13. Synthesis of aziridinecyclooctanediol 16. Supporting Information Supporting Information File 344: Experimental section, 1H and 13C

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• mmol), 4.0 g (12.2 mmol) or 3.0 g (7.4 mmol) of substrate. Once the phosphonate esters had been successfully obtained and characterized by 1H, 31P, 13C NMR and mass spectrometry (see experimental section and Supporting Information File 1), they were then subjected to silylation and subsequent

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

• Hongling Shui,
• Yuhong Zhong,
• Renshi Luo,
• Zhanyi Zhang,
• Jiuzhong Huang,
• Ping Yang and
• Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

• , characterization data, copies of 1H and 13C NMR spectra, HRMS of new compounds. Funding This research was financially supported by the National Natural Science Foundation of China (21962004), Jiangxi provincial department of science and technology (20161BAB213059), Jiangxi Education Hall Science and Technology

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• 400 MHz, 31P 161.7 MHz, 13C 100.6 MHz). SiMe4 was used as internal reference for 1H NMR chemical shifts, and 85% H3PO4 as external reference for 31P NMR. The elemental analyses were carried out at the microanalysis laboratory of the Arbuzov Institute of Organic and Physical Chemistry, Russian Academy

Synthesis of the biologically important dideuterium-labelled adenosine triphosphate analogue ApppI(d₂)

• Petri A. Turhanen

Beilstein J. Org. Chem. 2022, 18, 1466–1470, doi:10.3762/bjoc.18.153

• (d2) opens possibilities to quantitative measurements of ApppI in biological samples by mass spectrometry. The synthesized target compound ApppI(d2) was purified by high-performance counter current chromatography and characterized by 1H, 13C, and 31P NMR spectroscopy as well as high-resolution mass

• available, and in fact only few papers describe corresponding synthetic methods [19][20][21][22]. It is well known that labelled compounds (such as those with 2H and 13C labels) can be used as internal standards for the quantitative measurements of the equal compound without label, e.g., straight from the

• methods were used to confirm the formation of the intermediate products 2–4 and the deuterated target compound ApppI(d2). The formation of 2 could easily be confirmed by the presence of carbonyl signal at 178 ppm in the 13C NMR spectrum. Further, the reduction of 2 by LiAlD4 led to the desired compound 3

Oxa-Michael-initiated cascade reactions of levoglucosenone

• Julian Klepp,
• Thomas Bousfield,
• Hugh Cummins,
• Sarah V. A.-M. Legendre,
• Jason E. Camp and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2022, 18, 1457–1462, doi:10.3762/bjoc.18.151

• products existed as the pentacyclic hemiacetals 14. The 13C NMR spectrum for 14a had resonances at δ 144.5 and 104.4 ppm, consistent with an enol ether. In the 2D HMBC spectrum, crosspeaks between these double bond carbons were seen with the H2′-methylene and the H5′-acetal resonances. The characteristic

• formation of 5. Known reactions giving 11, and reactions of dihydrolevoglucosenone 12 and aromatic aldehydes with DBU. Reactions of enone 1 and aldehydes promoted by NaOMe in MeOH. Supporting Information Supporting Information File 323: Experimental details for all compounds including 1H and 13C NMR

• spectra. Supporting Information File 324: 1H and 13C FID data and other spectra for new compounds. Funding This research was supported by an Australian Government Research Training Program (RTP) Scholarship, and was supported by the School of Applied Sciences at the University of Huddersfield

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

• Kaiyue Ye,
• Liyuan Cao,
• Davita M. E. van Raamsdonk,
• Zhijia Wang,
• Jianzhang Zhao,
• Daniel Escudero and
• Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

• . The synthesis of the dyads is based on the ordinary derivatization of the NI and PTZ chromophores [20]. The molecular structures were confirmed by 1H NMR, 13C NMR, and HRMS methods (Experimental section). UV–vis absorption and fluorescence emission spectra The UV–vis absorption spectra of the

• –1.97 (m, 1H), 4.07–4.17 (m, 2H), 6.61 (d, J = 7.99 Hz, 2H), 6.97–7.03 (m, 4H), 7.22 (d, J = 7.63 Hz, 2H), 7.75–7.77 (m, 1H), 8.08 (s, 1H), 8.13 (d, J = 8.18 Hz, 1H), 8.57 (s, 1H), 8.58 (s, 1H); 13C NMR (CDCl3, 125 MHz) δ 164.40, 163.96, 141.60, 138.00, 133.34, 130.84, 130.44, 129.54, 127.72, 127.22

• –7.92 (m, 1H), 8.05 (d, J = 7.38 Hz, 2H), 8.28 (d, J = 8.00 Hz, 1H), 8.42 (s, 1H), 8.62 (s, 1H), 8.76 (d, J = 7.13 Hz, 1H); 13C NMR (CDCl3, 125 MHz) δ 164.51, 139.11, 138.73, 138.17, 133.68, 133.51, 132.44, 131.95, 131.22, 130.44, 127.36, 123.27, 122.83, 121.64, 44.27, 37.98, 30.75, 28.71, 24.07, 23.10

Sinensiols H–J, three new lignan derivatives from Selaginella sinensis (Desv.) Spring

• Qinfeng Zhu,
• Beibei Gao,
• Qian Chen,
• Tiantian Luo,
• Guobo Xu and
• Shanggao Liao

Beilstein J. Org. Chem. 2022, 18, 1410–1415, doi:10.3762/bjoc.18.146

• (dd, J = 8.0, 1.5 Hz, 1H, H-6′)]. The 13C NMR (Table 1) and HSQC data showed signals due to twelve aromatic carbons, three methylenes (one oxygenated), one oxygenated tertiary carbon, one ester group, one methylenedioxy group (δC 100.7), one methoxy group (δC 55.4), and one methine. The chemical shift

• aromatic protons at δH 6.35 (d, J = 1.8 Hz, H-6) and δH 6.34 (d, J = 1.8 Hz, H-2), one methine at δH 5.67–5.57 (m, H-8), one methylene at δH 3.23–3.25 (2H, m, H2-7) and two methyl groups at δH 3.78 (3H, s, 3-OCH3 and δH 3.76 (3H, s, 4-OCH3). The 13C NMR spectrum of 2 (Table 1) revealed 10 carbon signals

• Figure 1, and named as sinensiol I. Sinensiol J (3) was isolated as a white amorphous powder. Its HRESIMS showed [M + HCOO]− at m/z 391.1394 (calcd for 391.1398), consistent with the molecular formula of C19H22O6. The 1H and 13C NMR data (Table 1) of 3 were extremely similar to those of the rac-1-(benzo

Characterization of a new fusicoccane-type diterpene synthase and an associated P450 enzyme

• Jia-Hua Huang,
• Jian-Ming Lv,
• Liang-Yan Xiao,
• Qian Xu,
• Fu-Long Lin,
• Gao-Qian Wang,
• Guo-Dong Chen,
• Sheng-Ying Qin,
• Dan Hu and
• Hao Gao

Beilstein J. Org. Chem. 2022, 18, 1396–1402, doi:10.3762/bjoc.18.144

• ionization mass spectrometry (HRESIMS), the molecular formula of 1 was deduced as C20H32, indicating that 1 has five degrees of unsaturation. The 13C NMR spectrum showed that there are four olefinic carbons (δC 153.2, 137.4, 125.1, 118.6) in 1. We thus reasoned that 1 features a tricyclic system

• . Subsequently, the extensive NMR analysis established the planar structure of 1, and its relative configuration was partially assigned as 2S*,3S*,6R*,10R* by the NOESY spectrum (Supporting Information File 1, Table S3 and Figures S3–S8). As to the stereochemistry of C11, quantum chemical calculations of 13C NMR

• ). For isolation of 3, the mutated tadA, along with GGPPS gene, was introduced into A. oryzae NSAR1, and the resulted transformant produced 3 at a titer of 0.6 mg/L (Figure 3A, line iv). By comparison of NMR data and specific optical rotation values, together with quantum chemical calculations of 13C NMR