Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• reactions were also described in the syntheses of carbasugars which are unnatural molecular motifs with broad interest in medicine [85]. A relevant example was described by Balci and co-workers for the preparation of quercitol derivatives (Scheme 35) [86]. In this case, gram to multigram-scale double

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• -dihydroxylation. The stereochemical outcome of these reactions is discussed. Keywords: carbasugars; one-pot reactions; ring-closing metathesis; syn-dihydroxylation; Introduction Derivatives of carbohydrates, in which the endocyclic oxygen atom is replaced with a methylene group are known as carbasugars [1]. Due

• well-known and recognizable group of carbasugars. The synthesis of these monocyclic compounds (such as 1 and 2, Figure 1) and evaluation of their biological properties remain a challenging and vital research area [8][9][10][11]. On the other hand, bicyclic analogs of cyclitols are not as well

• -documented as their monocylic counterparts. However, polyhydroxylated derivatives of decalin and hydrindane are interesting synthetic targets, since they can be regarded as conformationally locked carbasugars (3 and 4, Figure 1) [12][13][14][15]. Indeed, some of the bicyclic carbasugars were proven to

Carbasugar analogues of galactofuranosides: α-O-linked derivatives

• Jens Frigell and
• Ian Cumpstey

Beilstein J. Org. Chem. 2010, 6, 1127–1131, doi:10.3762/bjoc.6.129

• exemplify the method. Keywords: carbasugars; etherification; galactofuranose; glycomimetics; pseudodisaccharides; regioselective; Introduction Galactofuranose is found in nature as a component of glycoconjugates in many microorganisms [1][2]. Galactofuranosides with the α configuration are rather less

• structure 14, but not in 14x. Hence, compound 13 presumably arose from debenzylative cycloetherification by attack of O-6 on C1, C1 being the most electrophilic carbon in both inter- and intramolecular epoxide-opening reactions. To achieve the inversion of stereochemistry at C2 of the α-talo carbasugars

Synthesis of a new class of aminocyclitol analogues with the conduramine D-2 configuration

• Latif Kelebekli,
• Yunus Kara and
• Murat Celik

Beilstein J. Org. Chem. 2010, 6, No. 15, doi:10.3762/bjoc.6.15

• ]. Carba analogues of oligosaccharides (carbasugars), generated by replacing the endocyclic O-atom in a monosaccharide [1][2][3][4][5][6][7][8][9][10][11], are thought to be better drug candidates than natural sugars, since they are hydrolytically stable. Spurred on by the heightened interest in the design

Synthesis of chiral cyclohexanes and carbasugars by 6-exo-dig radical cyclisation reactions

• Rajeev K. Shrivastava,
• Elise Maudru,
• Gurdial Singh,
• Richard H. Wightman and
• Keith M. Morgan

Beilstein J. Org. Chem. 2008, 4, No. 43, doi:10.3762/bjoc.4.43

• gave mixtures of syn- and anti-alkynols 2a–2c which were separated following protection as methoxymethyl ethers. These were converted to the corresponding iodides which underwent 6-exo-dig radical cyclisation to afford chiral cyclohexanes and carbasugars. Oxidation of the primary alcohols 6a–b gave the

• corresponding aldehydes which on treatment with Grignard reagents afforded a mixture of alcohols. The corresponding iodides underwent similar 6-exo-dig cyclisation to give fully functionalised cyclohexanes. Keywords: carbasugars; cyclisation; cyclohexanes; 6-membered ring; stereoisomers; Introduction The use

• closure of a radical onto an alkyne [14]. In contrast there are fewer reports of the corresponding 6-exo-dig cyclisation to prepare fully functionalised cyclohexanes and carbasugars. The reason for this may be inferred from the observation that the formation of six-membered rings by a radical ring closure

Synthesis and glycosidase inhibitory activity of new hexa- substituted C8-glycomimetics

• Olivia Andriuzzi,
• Christine Gravier-Pelletier,
• Gildas Bertho,
• Thierry Prangé and
• Yves Le Merrer

Beilstein J. Org. Chem. 2005, 1, No. 12, doi:10.1186/1860-5397-1-12

• Diastabol®, Basen® and Glucor® or Precose®). Results In that context, new C8-carbasugars and related aminocyclitols have been targeted in order to study the effect of the enhanced flexibility and of the new spatial distribution displayed by these structures on their adaptability in the active site of the

• miglustat (N-nBu DNJ, Zavesa®) and miglitol (N-hydroxethyl DNJ, Glyset® or Diastabol®) have already found therapeutic applications in Gaucher's disease [11] and type 2 (non-insulino-dependant mellitus) diabetes, [12][13] respectively. In the past decade, works have been targeted to carbasugars originally

• new eight-membered carbasugars (Figure 2, A = OH) and related aminocyclitols (A = NHR) from C2-symmetrical L-ido- or D-manno- cyclooctene, easily available by ring closing metathesis of 1,9-diene derived from L-ido- or D-manno-bis-epoxide [33]. Thus, synthetic potentialities of the newly created