A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles

• Pavel A. Topanov,
• Anna A. Maslivets,
• Maksim V. Dmitriev,
• Irina V. Mashevskaya,
• Yurii V. Shklyaev and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162

• crystal X-ray analysis (CCDC 2201614). As evinced by the NMR data, only one diastereomer of product 3aa was obtained. Contrary to the isoxazole-annulated products of a [3 + 2] cycloaddition of nitrones to FPDs [35], product 3aa appears to be stable on storage in solution, which was confirmed by the fact

• that the NMR data remained unvaried after keeping the product in solution for one day. Next, the conditions (Table 1) of the model reaction of FPD 1a and diazooxindole 2a were optimized. The best yield of product 3aа (Table 1, entries 6 and 7) was obtained by the reaction performed in acetonitrile at

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

• mg as the ⋅5.25 TBA salt and 24 mg as the ⋅3.25 TBA salt, calculated total yield 11.4%, which was comparable to earlier results [20], see also HPCCC chromatogram in Supporting Information File 1). The product was obtained as very hygroscopic colorless foamy solid. NMR data for ApppI(d2)⋅3.25 TBA salt

• , 576.0631; found, 576.0630. All NMR data were comparable to those reported elsewhere for conventional ApppI [19][21]. Preparation of Jones reagent: CrO3 (25 g) was slowly and carefully added to conc H2SO4 (25 mL) with stirring. After complete addition, the formed mixture was further added in very small

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• bearing a free amino group (Scheme 4). However, this product was prone to a ring–chain isomerization forming an equilibrating mixture of azaadamantane 15, tris-imine 16, and bicycle 17 in solution as determined by NMR data (see Supporting Information File 1 for details). We were able to shift the

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

• for a benzene, one olefinic carbon, one methylene and two methoxy groups. The above mentioned 1D NMR data of 2 in combination with its molecular formula indicated that the compound must be a symmetrical dimeric benzene derivative. Further analysis of NMR data suggested that the structure of 2 was

• 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

• compounds Compound 1: pale yellow amorphous powder, 27.81 (c 0.32, MeOH); IR (KBr) νmax: 3540, 1764, 1515, 1445, 1247, 1035 cm−1; ECD (c 2.2 × 10−4 M, MeOH) λmax (Δε) 204 (+4.36), 231 (+1.79) nm; 1H and 13C NMR data, see Table 1; HRESIMS (m/z): [M − H]− calcd for C20H19O7, 371.1136; found, 371.1133

Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• in CDCl3 and THF-d8 on a Bruker AV Ultra Shield 400 MHz instrument. Absorption spectra were obtained with PG T80. NMR data are represented as follows: chemical shift (ppm), multiplicity (s = singlet, brs = broad singlet, d = doublet, t = triplet, q = quartet, m = multiplet), coupling constants in

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

• ). 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

• was switched from 208 nm to 254 nm, additional product 4 was detected (Figure 3B, lines i and ii), which was elucidated to be the highly oxygenated product of 1 through the exhaustive NMR analysis (Supporting Information File 1, Table S5 and Figures S26–S32). Based on NMR data and the fact that 4 is

Synthesis of C6-modified mannose 1-phosphates and evaluation of derived sugar nucleotides against GDP-mannose dehydrogenase

• Sanaz Ahmadipour,
• Alice J. C. Wahart,
• Jonathan P. Dolan,
• Laura Beswick,
• Chris S. Hawes,
• Robert A. Field and
• Gavin J. Miller

Beilstein J. Org. Chem. 2022, 18, 1379–1384, doi:10.3762/bjoc.18.142

• n-BuLi at −78 °C. This afforded protected anomeric phosphate 16, confirmed by 1H and 13C NMR data (H1 δH 6.01 ppm, 3JH1–P = 6.7 Hz, 3JH1–H2 = 1.8 Hz; C1 δC 96.1 ppm, 2JC1–P = 5.9 Hz). Following an initial purification of 16 using silica gel flash chromatography, the material was crystallised using a

• : Detailed experimental protocols and characterisation data; spectral NMR data (1H, 13C and 31P NMR for compounds 10–17 and 19). Acknowledgements A clone encoding for GDP mannose-pyrophosphorylase from S. enterica was kindly donated by T. L. Lowary. Funding UK Research and Innovation (UKRI, Future Leaders

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

• Irene Torres-García,
• Josefa L. López-Martínez,
• Rocío López-Domene,
• Manuel Muñoz-Dorado,
• Ignacio Rodríguez-García and
• Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

• . Analysis of the NMR data of the Mosher's derivatives of 8 suggested (S) configuration for the alcohol (−)-3 [16]. On the other hand, enantiopure acetate (+)-(R)-9 was transformed into diol (+)-(R)-7 by the addition of an excess of MeMgBr. Finally, these enantiopure compounds, α-hydroxyallene (−)-(S)-3 and

• those published for the allegedly dihydrorosefuran isolated from Artemisia pallens nor with those reported for the compound from Tagetes mendocina (see Table 1 and Table 2). The 13C NMR data of compound 1 are quite similar to those of the natural product isolated from T. mendocina, except for the

• signals of the oxygenated carbons (C2 and C5). The same behavior pattern can be observed in the 1H NMR data. This made us think that the natural product of T. mendocina could have an acyclic skeleton instead of a dihydrofuran one. For this reason, we propose this compound should be the diol called

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• ). Complex 4 was easily separated from the minor diastereomer by column chromatography. The structure and purity of (S)-4 was confirmed by NMR data, including HMBC, HSQC and COSY 2D techniques. The assignment of the α-stereocenter as (S) was based on the NOESY data (see Supporting Information File 1 and

New azodyrecins identified by a genome mining-directed reactivity-based screening

• Atina Rizkiya Choirunnisa,
• Kuga Arima,
• Yo Abe,
• Noritaka Kagaya,
• Kei Kudo,
• Hikaru Suenaga,
• Junko Hashimoto,
• Manabu Fujie,
• Noriyuki Satoh,
• Kazuo Shin-ya,
• Kenichi Matsuda and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2022, 18, 1017–1025, doi:10.3762/bjoc.18.102

• in the Refseq database. Nodes are colored according to the host organism’s order. Enzymes with known biosynthetic products are colored red. N2H4-detecting colorimetric assay. Proposed biosynthetic pathway of azodyrecin. 1H (500 MHz) and 13C (125 MHz) NMR data for azodyrecin D (7), azodyrecin E (8

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• 12 degrees of unsaturation based on the HRMS–ESI data (m/z 347.0893 [M + Na]+, calcd for C19H16O5Na+, 347.0890) (Figure S1, Supporting Information File 1). Comprehensive analysis of the 1H and 13C NMR data (Table 1, Figures S3 and S4, Supporting Information File 1) and HSQC data (Figure S5

• positions (Figure 2). The NMR data indicated that compound 1 shares a similar skeleton to the known compound (±)-tylopilusin B [18]. The additional signals suggested that three methines (δC/δH 59.2/4.49, CH-4; 129.0/7.27, CH-4’; 130.5/7.38, CH-4’’) in compound 1 were hydroxylated in (±)-tylopilusin B

• +, 289.0835) (Figure S7, Supporting Information File 1), and the unsaturation was 11 degree. It could be deduced that compound 2 also possesses a similar core to compound 1, based on the molecular formula and NMR data (Table 1, Figures S8–S13, Supporting Information File 1). This could be confirmed by the key

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