Synthesis of a Novel Polyhydroxylated Salicylic Acid Lactone Framework

Abstract

The facile preparation of a novel 8-membered polyhydroxylated salicylic acid lactone from 2,6-dihydroxybenzoic acid and sodium thio-D-glucose is described. The key step involved a sodium hydride promoted intramolecular lactonization in the presence of excess TMSCl, which led to isolation of the "natural product like" lactone.

Metathesis and Macrocycles with Embedded Carbohydrates

“…The RCM of 10 and 12 using catalyst 1A in dichloromethane followed by catalytic hydrogenation and deacetylation gave access to 11 (48 % for RCM) and 13 (80 % for RCM), respectively. Alkyne metathesis with 15 was carried out using Mo(CO) 6 and 2-fluorophenol in chlorobenzene at reflux. [8b,16] The acetate protecting groups were removed using sodium methoxide in methanol to give 16 (27 % for RCAM).…”

“…[2] Inevitably the synthetic routes to such compounds involves a macrocyclization step, which can prove challenging. The intramolecular Diels-Alder reaction, [3] aldol reactions, [4] copper catalysed azide-alkyne cycloaddition [5] and various lactonizations [6] have been used for formation of macrocycles. In recent years, metathesis [7] has become very popular.…”

Sodium Hydride

“…5 An effective route involves the reaction of enaminonitrile g-lactams derived from Nalkyl-a-bromoacetamides and malononitrile in the presence of NaH with acryloyl chloride derivatives. (D) A novel eight-membered polyhydroxylated salicylic acid lactone 6 was prepared from 2,6-dihydroxybenzoic acid and sodium thio-D-glucose. The key step involved a NaH-promoted intramolecular lactonization in the presence of excess TMSCl which led to the isolation of the 'natural product like' lactone.…”

“…(D) A novel eight-membered polyhydroxylated salicylic acid lactone 6 was prepared from 2,6-dihydroxybenzoic acid and sodium thio-D-glucose. The key step involved a NaH-promoted intramolecular lactonization in the presence of excess TMSCl which led to the isolation of the 'natural product like' lactone.…”

A catalyst-free, facile and efficient approach to cyclic esters: synthesis of 4H-benzo[d][1,3]dioxin-4-ones

“…For instance, Perlmutter and co-workers discovered that the reaction of phenyl salicylate with aldehydes could afford the corresponding cyclic products using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a base in 1996 (②, Scheme 1). 27 Salicylic acids can be converted into 4H-benzo[d] [1,3]-dioxin-4-ones by reacting with a ketone, catalyzed by N,N-4-dimethylamino-pyridine (DMAP) in the presence of stoichiometric SOCl 2 (③, Scheme 1) [8][9][10][11][12][13][14][15][16][17][18][19]28,29 and in a solution of triuoroacetic acid (TFA) and tri-uoroacetic anhydride (④, Scheme 1). 5,[20][21][22] Instead of TFA and triuoroacetic anhydride, catalytic amounts of sulfuric acid (H 2 SO 4 ) and stoichiometric acetic anhydride can be used to prompt this transformation.…”