Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• synthesis by Taber that used dichromate as an oxidant [13] led to a less diastereoselective reaction furnishing the three ketones 9, 10, and 11 in a ratio of 36:2:5. The cis-conformation of the decalin backbone of 9 and 11 originates from the endo-selectivity of the Diels–Alder reaction and the boat

Stereoselective nucleophilic addition reactions to cyclic N-acyliminium ions using the indirect cation pool method: Elucidation of stereoselectivity by spectroscopic conformational analysis and DFT calculations

• Koichi Mitsudo,
• Junya Yamamoto,
• Tomoya Akagi,
• Atsuhiro Yamashita,
• Masahiro Haisa,
• Kazuki Yoshioka,
• Hiroki Mandai,
• Koji Ueoka,
• Christian Hempel,
• Jun-ichi Yoshida and
• Seiji Suga

Beilstein J. Org. Chem. 2018, 14, 1192–1202, doi:10.3762/bjoc.14.100

• the addition of nucleophiles to N-acyliminium ions. The substituent at the nitrogen atom is omitted for clarity. A plausible mechanism of the observed diastereoselective reaction of the N-acyliminium ions. Comparison of ΔG for the pseudo-equatorial and pseudo-axial conformations of C1–C6 at the B3LYP

Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes

• M. Emin Cinar,
• Bernward Engelen,
• Martin Panthöfer,
• Hans-Jörg Deiseroth,
• Jens Schlirf and
• Michael Schmittel

Beilstein J. Org. Chem. 2016, 12, 813–824, doi:10.3762/bjoc.12.80

• aldehydes in the presence of metal halides to furnish tetrahydro-2H-pyran-2,4-diols in a highly diastereoselective manner, is investigated thoroughly by experiments and computations. The reaction was also successfully implemented on a flow micro reactor system. Keywords: DFT; diastereoselective reaction

Diastereoselective radical addition to γ-alkyl-α-methylene-γ-butyrolactams and the synthesis of a chiral pyroglutamic acid derivative

• Tomoko Yajima,
• Eriko Yoshida and
• Masako Hamano

Beilstein J. Org. Chem. 2013, 9, 1432–1436, doi:10.3762/bjoc.9.161

• the reaction were also revealed. This stereoselective radical reaction was used for synthesis of chiral pyroglutamic acid derivatives starting from a commercially available chiral amino acid. Keywords: chelation controlled reaction; diastereoselective reaction; free radical; lactams; pyroglutamic

Rh(III)-catalyzed directed C–H bond amidation of ferrocenes with isocyanates

• Satoshi Takebayashi,
• Tsubasa Shizuno,
• Takashi Otani and
• Takanori Shibata

Beilstein J. Org. Chem. 2012, 8, 1844–1848, doi:10.3762/bjoc.8.212

• longer reaction time, but alkyl isocyanates were also available. We next examined a diastereoselective reaction using a commercially available chiral oxazolyl ferrocene 1b, and the reaction was conducted under the same reaction conditions used in Table 2. Several isocyanates were submitted to the

• example of catalytic methods to construct planar chiral ferrocenes. We are currently investigating an enantioselective reaction. The ORTEP drawing of 3c with 30% probability ellipsoids, and Flack absolute structure parameter of 0.003(12). Screening of catalysts. Scope of isocyanates. Diastereoselective

• reaction by using chiral oxazolyl ferrocene 1b. Supporting Information Supporting Information File 423: Experimental procedures and physical properties of new compounds. Supporting Information File 424: CIF of complex 3c. Acknowledgements This work was supported by the Japan Society for the Promotion of

Brønsted acid-promoted azide–olefin [3 + 2] cycloadditions for the preparation of contiguous aminopolyols: The importance of disiloxane ring size to a diastereoselective, bidirectional approach to zwittermicin A

• Hubert Muchalski,
• Ki Bum Hong and
• Jeffrey N. Johnston

Beilstein J. Org. Chem. 2010, 6, 1206–1210, doi:10.3762/bjoc.6.138

• alcohol protecting group at the central anti-1,3-diol (C11 and C13 in zwittermicin A). Our study of the diastereoselective reaction of benzyl azide with the bis(imide) is presented in Table 1. We began with a thermal reaction of the bis(imide) 5 that used the common di(tert-butylsilyl) functionality as a

Asymmetric aza-Diels- Alder reaction of Danishefsky's diene with imines in a chiral reaction medium

• Bruce Pégot,
• Olivier Nguyen Van Buu,
• Didier Gori and
• Giang Vo-Thanh

Beilstein J. Org. Chem. 2006, 2, No. 18, doi:10.1186/1860-5397-2-18

• asymmetric induction is strong intermolecular interactions like electrostatic attraction and hydrogen bonding between ionic solvents and intermediates or transition states of the diastereoselective reaction step (Figure 1). This observation was made by our group[25] and further confirmed by Leitner and co