On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• {1,1} (0.08 g, 3%) and then compound 3{1,1} (1.86 g, 76%) both as white powders. 3-Methyl-5-phenylpyrazin-2-ol (3{1,1}): NMR data were identical with those observed for the substance obtained via aromatization of 3-methyl-6-phenylpiperazin-2-one [34]. 1H NMR (DMSO-d6) δ 12.28 (br s, 1H), 7.85 (m, 3H

• } (1.71 g, 66%) both as white powders. 3-Benzyl-5-phenylpyrazin-2-ol (3{1,2}): NMR data were identical with those reported [29]. 3-Benzyl-6-phenylpyrazin-2-ol (4{1,2}): HRMS (m/z): [M + H]+ calcd for C17H15N2O, 263.1178; found, 263.1179. 1H NMR (DMSO-d6) δ 12.27 (br s, 1H), 7.82 (m, 3H), 7.48 (m, 3H

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• (+)-1 also being an aromadendrane-type sesquiterpenoid containing a gem-dimethylcyclopropyl unit [δH 0.80 (dd, J = 10.6, 9.6 Hz, H-6), 0.68 (m, H-7), 1.07 (s, 12-Me), 1.19 (s, 13-Me)]. Further literature survey revealed that the overall 1D and 2D NMR data of compound (+)-1 (Table 1), except the optical

• as depicted in Figure 1, and named (+)-ximaocavernosin P. Compounds 4 and 5 showed NMR data diagnostic of tetrahydronaphthalene-bearing cadinane-type sesquiterpenoids, in line with the co-occurring compounds 6 and 7. In addition, 4 and 5 as optically inactive white powder implied the possibility that

• cadinane-type sesquiterpenoid of plant origin (leaves and stems of Manglietia insignis) [21], based on their identical 1H and 13C NMR data (Table 1 and Figures S16–S20 in Supporting Information File 1). Since the relative configuration of 4 (7S*, 10R*) was assigned, its absolute configuration was worth to

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• this work, especially Robin Stein and Tara Sprules on the NMR data, Hatem Titi on SCXRD interpretation, Nadim Saadé and Alexander Wahba on HRMS, and Petr Fiurasek and Ehsan Hamzehpoor on UV–vis spectroscopy. Funding The authors acknowledge the Canada Research Chair (Tier I) foundation, the E.B. Eddy

Terpenoids from Glechoma hederacea var. longituba and their biological activities

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

• -hydroxy-glechoman-8,12-olide (DHG) indicated that 1 could be the glucopyranosyl-DHG [8]. The HMBC cross peak from H-1' (δH 4.20) to C-8 (δC 109.2) suggested a glucopyranosyl unit located at C-8 (Figure 2A). The relative configuration of 1 was established based on comparison of 1H NMR data with the

• of 2 was established as (1R,4R,5S,6S,8S,10S)-1,10;4,5-diepoxy-6-O-β-ᴅ-glucopyranosyl-8-methoxy-glechoman-8,12-olide. Compound 3 was obtained as a colorless gum. The HRESIMS spectrum of 3 provided a molecular formula C21H30O9 (m/z 449.1789 [M + Na]+, calcd for C21H30O9Na, 449.1788). The 1H NMR data of

• identified as ent-kauran-3α,12α,16α-triol 3-O-β-ᴅ-glucopyranoside. Compound 5 was obtained as a colorless gum. Based on its HRESIMS and NMR data, its molecular formula was determined as C28H46O9 (m/z 549.3031 [M + Na]+, calcd for C28H46O9Na, 549.3040). The 1H NMR spectrum of 5 showed four methyl groups [δH

Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities

• Viktor A. Zapol’skii,
• Isabell Berneburg,
• Ursula Bilitewski,
• Melissa Dillenberger,
• Katja Becker,
• Stefan Jungwirth,
• Aditya Shekhar,
• Bastian Krueger and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2022, 18, 524–532, doi:10.3762/bjoc.18.54

• shifts of the pyrazole ring and the dichloromethyl group of 3-aminopyrazoles 5b–k are 151.1–154.0 ppm (C-NRR1), 120.6–122.2 ppm (C-NO2), 136.7–136.9 ppm (C-CHCl2), and 57.5–57.7 ppm (CHCl2). The obtained 13C NMR data of pyrazoles 5 match the calculated NMR shifts (Table S1 in Supporting Information File

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• . Structures of compounds 1–7 isolated from Trichoderma citrinoviride PSU-SPSF346. 1H-1H COSY, key HMBC, and NOEDIFF data of compounds 1 and 2. ECD spectra of compounds 1 and 3 in MeOH. Proposed biosynthetic pathway for compound 2. The NMR data of compounds 1 and 2 in CD3OD. Supporting Information Supporting

Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea

• Di Zhang,
• Zhe Wang,
• Xiao Han,
• Xiao-Lei Li,
• Zhong-Yu Lu,
• Bei-Bei Dou,
• Wen-Ze Zhang,
• Xu-Li Tang,
• Ping-Lin Li and
• Guo-Qiang Li

Beilstein J. Org. Chem. 2022, 18, 374–380, doi:10.3762/bjoc.18.42

• polyhydroxylated steroids lobophysterols E–H (1–4), together with three known compounds (5–7), were isolated from the soft coral Lobophytum pauciflorum collected at Xisha Island, China. The structures of the new compounds were elucidated by extensive spectroscopic analysis and comparison with NMR data of

• . Its molecular formula was established as C30H50O3 by HRESIMS from the molecular ion peak at m/z 481.3648 [M + Na]+. The 1H NMR data (Table 1) showed 5 methyl singlets (δH 0.76, CH3-19; δH 0.84, CH3-18; δH 1.19, CH3-26; δH 1.19, CH3-27; δH 1.67, CH3-21), 3 methyl doublets (δH 0.81, CH3-29; δH 0.84, CH3

• powder with molecular formula C29H48O4, established by HREIMS at m/z 483.3446 [M + Na]+. The 1H and 13C NMR data (Table 1) of 2 exhibited very similar typical features of compound 1, the difference between the two compounds occurred in ring A: an OH was located at C-5, but a missing methyl group at C-4

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• the basis of 2D NMR data. In the HMBC spectrum, the singlet methyl protons H3-17 and H3-18 show correlations to C-7, a quaternary carbon at 47.4 ppm (C-8), and an oxymethine carbon at 80.3 ppm (C-9). COSY and HMBC data established the alkyl chain from CH-9 to CH3-16. A correlation between H-9 and C-19

• consistent with a molecular formula of C36H53N5O9 (calcd for C36H54N5O9, 700.3922). The difference of 16 mass units in comparison to compound 1 suggests the presence of an additional oxygen atom. Comparison of the NMR data with 1 reveals the most significant chemical shift deviations in the α-amino-ε

• oxygen atom. A comparison of the NMR data with 3 revealed that the chemical shifts of CH2-24 are significantly shifted upfield. In contrast, all other resonances are highly conserved and no difference in the splitting pattern was observed. This suggests the presence of an electron-donating hydroxy group

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• compounds Compound 1: Pale yellow powder; [α]D25 –38.05 (c 0.1, MeOH); UV (MeOH) λmax nm (log ε) 290 (0.35), 324 (0.32); IR νmax: 3266, 2925, 1739, 1701, 1624, 1457, 1261, 1020, 802, 611, 405 cm–1; 1H, 13C NMR data, see Table 1; ESIMS (positive ion mode): (m/z) 617 [M + H]+; HRESIMS (positive ion mode): (m

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• the complete NMR data can be found in Supporting Information File 1. This enamine moiety reacts with a cinnamaldehyde compound 3 to give the desired product. Here, the role of the catalyst is to activate the cinnamaldehyde species 3. The nickel of the catalyst coordinates to the oxygen atom of the

Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• remaining four methylenes (H6, H7, H8, H9) were not assignable from the NMR data due to signal overlapping, but were expected to be placed between the isohexyl and the alkenyl fragments, thus establishing an isopentadecenoyl moiety. The connectivity between this aliphatic chain to the tandem

• compounds 1 and 2 (m/z 623, 441, 423, and 241, Figure S28 and Scheme S29 in Supporting Information File 1), supporting a saturated fifteen-carbon acyl moiety in compound 3. This assignment was corroborated by substantially the same NMR data for the remaining part of 1–3. Thus, 3 was concluded to be a

• acquired on a quadrupole time-of-flight mass spectrometer in the negative ion mode. MS/MS fragmentation pathway for compound 1. 1H and 13C NMR data for tenacibactin K (1) in DMSO-d6. 1H and 13C NMR data for tenacibactins L (2) and M (3) in DMSO-d6. Cytotoxicity data of compounds 1–3. Supporting

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• absolute configuration of 12 experimentally. For this purpose, compound 12 was re-isolated from patchouli oil and its NMR data were fully assigned (see Supporting Information File 1, Table S4 and Figures S13–S20). Since 12 is also a side product of PTS, the data obtained from the above described labelling

• indicate 13C-labelled carbons. Labelling experiments on the biosynthesis of patchoulol (3, part 2). Black dots indicate 13C-labelled carbons. NMR data of compound 17 (700 MHz, C6D6). Supporting Information Supporting Information File 24: Experimental details, characterisation data and copies of spectra

Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes

• Shun Saito,
• Kanji Indo,
• Naoya Oku,
• Hisayuki Komaki,
• Masashi Kawasaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203

• 13C NMR data, and high-resolution ESIMS data were presented. While an S-configuration was assigned for phialomustin B based on its positive specific rotation ([α]D25 +55.5, c 1.5, CHCl3) in comparison with those of synthetic standards [26], opposite negative signs in CHCl3 and MeOH ([α]D27 –12, c

• mg, tR = 32.1 min). (2E,4E)-2,4-Dimethyl-2,4-octadienoic acid (1): yellow oil; UV (MeOH) λmax (log ε) 264 (4.08) nm; IR (ATR) νmax: 2959, 2610, 1679, 1622, 1417, 1269, 1138, 1012, 926 cm–1; 1H and 13C NMR data, see Table 1 and Table 2; HR–ESI–TOFMS (m/z): [M + Na]+ calcd for C10H16NaO2, 191.1043

• ; found, 191.1044. (2E,4E)-2,4,7-Trimethyl-2,4-octadienoic acid (2): yellow oil; UV (MeOH) λmax (log ε) 260 (4.04) nm; IR (ATR) νmax: 2957, 1681, 1622, 1417, 1269, 1137 cm–1; 1H and 13C NMR data, see Table 1 and Table 2; HR–ESI–TOFMS (m/z): [M + Na]+ calcd for C11H18NaO2, 205.1199; found, 205.1202. (R

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• data are reported as follows: chemical shift values (ppm), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet), coupling constant and relative integral. 13C NMR spectra were obtained using a Bruker AVANCE AV 400 at 100 MHz in CDCl3, CD3OD or D2O. 13C NMR data are reported

• procedures. 1H NMR spectra were obtained using a Bruker AVANCE AV 400 spectrometer at a frequency of 400 MHz, respectively in CDCl3, CD3OD or D2O. Chemical shifts are reported in parts per million (ppm) and coupling constants in Hertz (Hz). The residual solvent peaks were used as internal standards. 1H NMR

Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies

• Tanmoy Halder and
• Somnath Yadav

Beilstein J. Org. Chem. 2021, 17, 2915–2921, doi:10.3762/bjoc.17.199

• , DEPT-135, 13C NMR, COSY, and HSQC as well as mass spectrometry using HRMS. The NMR data were found to correlate well with the data reported for the natural polysaccharide [38]. Conclusion In conclusion, the trisaccharide repeating unit of the O-polysaccharide of Providencia stuartii O49 in its p

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• methides with TosMIC.a Supporting Information Supporting Information File 374: General information, characterization data, and copies of 1H and 13C NMR spectra. Acknowledgements We would like to thank Ms H. Z. Liu for obtaining the LC–MS and NMR data. Funding We gratefully acknowledge the National

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• were no significant differences in the chemical shift values between the quinoline precursor and new Schiff bases regarding the aromatic resonances in the 1H NMR and 13C NMR data. Studies in the literature have reported that the imine group may exist as E/Z geometrical isomers in the –CH=N double bond

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

• Lukáš Ďurina,
• Anna Ďurinová,
• František Trejtnar,
• Ľuboš Janotka,
• Lucia Messingerová,
• Jana Doháňošová,
• Ján Moncol and
• Róbert Fischer

Beilstein J. Org. Chem. 2021, 17, 2781–2786, doi:10.3762/bjoc.17.188

• -methoxycinnamaldehyde (6). Thus, the reaction of 6 with N-Cbz-protected hydroxylamine 7 catalyzed by ᴅʟ-proline in chloroform gave racemic 5-hydroxyisoxazolidine 8 in 77% yield almost as a sole trans isomer (dr > 9:1). Its structure was confirmed by comparison with already reported NMR data for the known (3S,5S

• -(hydroxyamino)-α,β-diol 4 (dr > 95:5) in 73% yield (Scheme 3). Its relative configuration was determined by comparison with already reported NMR data of related γ-(hydroxyamino)-α,β-diols [17]. More specifically, the value of the vicinal coupling constant J2,3 = 1.8 Hz and the chemical shift of the H-2 proton

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• -triazine derivatives. Molecular structures of compounds 12h (A) and 13c (B) representing both possible regioisomers of the alkylation reaction (displacement parameters are drawn at the 50% probability level). The X-ray data corroborate the obtained NMR data. Graphical overview about selected pyrazolo[1,2,3

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

• -layer chromatography (TLC). Organic compounds were purified using commercial Merck silica gel (0.043–0.06 mm) with a fluorescence indicator (the visualization was performed under UV light at 254 nm). All solvents for work-up and column chromatography were distilled before use. NMR data were recorded in

Synthesis of 5-arylacetylenyl-1,2,4-oxadiazoles and their transformations under superelectrophilic activation conditions

• Andrey I. Puzanov,
• Dmitry S. Ryabukhin,
• Anna S. Zalivatskaya,
• Dmitriy N. Zakusilo,
• Darya S. Mikson,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2417–2424, doi:10.3762/bjoc.17.158

• ), oxadiazole 3a gave the product of hydration of the acetylene bond (4d, yield of 65%) existing in solution as equilibrium between ketone and enol forms in a ratio of 1.2:1 according to NMR data (see Supporting Information File 1). Then, reactions of 5-acetylenyl-1,2,4-oxadiazole 3a–d with arenes (benzene and

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• secondary metabolites 1–5 including pseudomonin A–C (1–3) and pseudomobactins A and B (4 and 5). The two known compounds, pseudomonine (6) and salicylic acid (7) were also isolated as the major constituents of the extracts and their structures were determined by analysis of HRESIMS, 1D and 2D NMR data (see

• that revealed a molecular ion at m/z 237.0874 (calcd for C11H13N2O4−, 237.0880). A thorough analysis of 1H and 2D NMR data (see Table 1 and Supporting Information File 1) showed four aromatic methines, two aliphatic methines, one methyl, and four quaternary carbons signals at δC 162.9 (C-1), 113.2 (C-6

• −9.5 (c 0.02, MeOH); UV (MeOH) λmax, nm (log ε): 276 (3.23); IR (cm−1) νmax: 3333, 1677 1660, 1538, 1493, 1203, 1138; NMR data, see Table 1; HRESIMS (m/z): [M − 1]− calcd for C11H13N2O4, 237.0880; found, 237.0874, Δ = −2.53 ppm. Pseudomonin B (2): yellowish oil; [α]D25 −13.3 (c 0.05, MeOH); UV (MeOH

Phenolic constituents from twigs of Aleurites fordii and their biological activities

• Kyoung Jin Park,
• Won Se Suh,
• Da Hye Yoon,
• Chung Sub Kim,
• Sun Yeou Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151

• (1–3), a new phenolic glycoside (15), a new cyanoglucoside (16), and 14 known compounds (4–14 and 17–19) (Figure 1). Compound 1 was obtained as a colorless gum. The molecular formula was determined to be C25H32O11 from the [M + Na]+ molecular ion peak in the positive mode HRFABMS. The 1H NMR data

• 5.51 (d, J = 6.1 Hz, H-7)], an anomeric proton of a sugar [δH 4.27 (d, J = 7.8 Hz, H-1′′)], and a methoxy group [δH 3.84 (s, 3-OCH3)]. The 13C NMR data (Table 1) showed 25 peaks including 12 aromatic carbons [δC 147.6 (C-3), 145.9 (C-4), 145.1 (C-4′), 140.4 (C-3′), 135.2 (C-1′), 133.7 (C-1), 128.3 (C-5

• -rhamnopyranoside and was named as aleuritiside B. Compound 3 was obtained as a colorless gum after purification with a molecular formula of C26H36O11 as deduced from the positive molecular ion peak [M + Na]+ at m/z 547.2155 (calcd for C26H36O11Na, 547.2155) in the HRESIMS. Analysis of the 1H and 13C NMR data

Nomimicins B–D, new tetronate-class polyketides from a marine-derived actinomycete of the genus Actinomadura

• Zhiwei Zhang,
• Tao Zhou,
• Taehui Yang,
• Keisuke Fukaya,
• Enjuro Harunari,
• Shun Saito,
• Katsuhisa Yamada,
• Chiaki Imada,
• Daisuke Urabe and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2194–2202, doi:10.3762/bjoc.17.141

• ). Nomimicin B (1) Colorless amorphous solid; [α]D23 −29 (c 0.10, MeOH); UV (MeOH) λmax (log ε) 246 (3.83), 293 nm (3.71); ECD (c 9.5 × 10−5, MeOH) λext (Δε) 208 (−5.27), 247 (+3.72), 294 nm (−1.24); IR νmax: 3360, 2965, 1755, 1619, 1408, 1088, 998 cm−1; see Table 1 for 1H and 13C NMR data; HRESITOFMS (m/z

• , 1007 cm−1; see Table 1 for 1H and 13C NMR data; HRESITOFMS (m/z): [M + Na]+ calcd for C30H40O7Na, 535.2666; found, 535.2665. Nomimicin D (3) Colorless amorphous solid; [α]D23 −70 (c 0.10. MeOH); UV (MeOH) λmax (log ε) 243 (3.99), 302 nm (3.54); IR νmax: 3380, 2963, 1723, 1619, 1413, 1258, 1010 cm−1

• ; see Table 2 for 1H and 13C NMR data; HRESITOFMS (m/z): [M + Na]+ calcd for C30H40O6Na, 519.2717; found, 519.2717. Nomimicin A (4) Colorless amorphous solid; [α]D23 −87 (c 0.10. CHCl3, lit. [α]D23 −94 (c 0.10. CHCl3) [15]); UV (MeOH) λmax (log ε) 242 (3.73), 298 nm (3.59); ECD (c 1.0 × 10−4, MeOH) λext

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• before use. NMR data were recorded on Bruker ARX 300 instruments in CDCl3 with tetramethylsilane as the internal standard (signals due to the solvent; CHCl3: δ 7.26 for 1H and δ 77.16 for 13C). The 1H NMR chemical shifts and coupling constants were determined assuming first-order behavior. Peak