Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• , this study should be of general interest in the understanding of weak interactions that are now important to so many areas of chemistry, such as crystal engineering and supramolecular chemistry. Synthesis of trihalogenated pyrans: a) Chiron approach to multivicinal inter-halide derived from

• chiral halides: F, Cl, Br, I) [19]. Only a handful of natural product syntheses have been reported [20][21], despite the promising biological activity of these unique inter-halides [22]. For our part, we recently reported the synthesis of contiguous inter-halide-bearing stereocenters using a Chiron

• approach from levoglucosan 1 (Figure 1a) [23]. Allopyranose inter-halides 4 incorporating the 2,3-cis, 3,4-cis relationship for the halogens were prepared via intermediates 2 and 3 from levoglucosan (1). Compounds 4 were the starting point to complex 2,3,4-trihalohexanetriols and 2,3,4,5

Fluorine effect in nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-D-hexopyranose

• Danny Lainé,
• Vincent Denavit,
• Olivier Lessard,
• Laurie Carrier,
• Charles-Émile Fecteau,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2020, 16, 2880–2887, doi:10.3762/bjoc.16.237

• progress to the development of innovative synthetic methodology to access polyfluorosugars [18]. For our part, we recently described the preparation of multi-vicinal trifluorinated hexopyranose analogues 6–9 using the Chiron approach from levoglucosan (1, Figure 1) [19]. Various 1,6-anhydro-2,3-dideoxy-2,3

A carbohydrate approach for the formal total synthesis of (−)-aspergillide C

• Pabbaraja Srihari,
• Namballa Hari Krishna,
• Ydhyam Sridhar and
• Ahmed Kamal

Beilstein J. Org. Chem. 2014, 10, 3122–3126, doi:10.3762/bjoc.10.329

• , utilizing a Trost hydrosilylation and protodesilylation as key reactions. Keywords: alkynylation; chiron approach; Ferrier-type C-glycosylation; macrolide; Introduction Aspergillides A, B and C (Figure 1) (three, novel, bicyclic, 14-membered macrolides with 2,6-cis or trans-fused di- or tetrahydropyan

• approach has been a conventional strategy to achieve the total synthesis of complex, natural products with known handedness. Herein we disclose our strategy for the formal total synthesis of (−)-aspergillide C in a concise manner following the chiron approach. Retrosynthetic Analysis Through a

• present context, we have focused on a chiron approach for the synthesis of aspergillide C and thus chose commercially available tri-O-acetyl-D-galactal as the raw material, which can be directly utilized for the synthesis of the dihydropyran motif. The side arm fragment 10 was readily available in large

Synthesis of (2S,3R)-3-amino-2-hydroxydecanoic acid and its enantiomer: a non-proteinogenic amino acid segment of the linear pentapeptide microginin

• Rajendra S. Rohokale and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2014, 10, 667–671, doi:10.3762/bjoc.10.59

• -hydroxy-β-aminodecanoic acid (AHDA, 2a) and its enantiomer 2b. The enantiomer of 2a is the N-terminal part of the natural linear pentapeptide microginin, which is used as an antihypertensive agent. Keywords: AHDA; carbohydrate; chiron approach; enantioselective; natural products; non-proteinogenic amino

A versatile and efficient approach for the synthesis of chiral 1,3-nitroamines and 1,3-diamines via conjugate addition to new (S,E)-γ-aminated nitroalkenes derived from L-α-amino acids

• Vera Lúcia Patrocinio Pereira,
• André Luiz da Silva Moura,
• Daniel Pais Pires Vieira,
• Leandro Lara de Carvalho,
• Eliz Regina Bueno Torres and
• Jeronimo da Silva Costa

Beilstein J. Org. Chem. 2013, 9, 832–837, doi:10.3762/bjoc.9.95

• combinations of both [42][43][44]. Nonetheless, the use of chiral nitroalkenes bearing a stereogenic center in the γ-position in nonracemic diastereoselective syntheses ("chiron" approach [45]) is less frequent in the literature. Notably, chiral nitroalkenes derived from carbohydrates [46][47][48][49][50] have

• enantioselective synthesis as chiral auxiliaries, chiral catalysts, chiral reagents and chiral ligands [59][60]. In our continuing interest in synthesizing new chiral nonracemic nitro compounds [61][62][63][64][65][66][67][68] by a "chiron" approach [45], we intended to develop a route for obtaining γ-nitrogenated

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• remained unknown. In 1998, Hanessian’s group [28] reported the stereocontrolled first total synthesis of a diastereomer of the presumed mono-THF type acetogenin annonacin A utilizing the “Chiron approach” (Scheme 4). The well-known lactone 30 obtained from L-glutamic acid was elaborated to a lactone