Syntheses of l-Threose and Methyl Di-O-acetyl-l-threuronate from dextro-Tartaric Acid

Abstract

Reduction of methyl hydrogen di-O-acetyl-dextro-tartrate (I) with sodium borohydride in water afforded l-threono-γ-lactone (II). l-Threose (IV) was obtained on treatment of the γ-lactone (II) with an excess of disiamylborane. Reduction of ester chloride of di-O-acetyl-dextro-tartaric acid (VI) with tri-n-butyltin hydride yielded methyl di-O-acetyl-l-threuronate (VII). Attempts to reduce 2-deoxy-pentarate ester (X) derived from ester chloride (VI) via diazoketone (VIII) with sodium borohydride to give 2-deoxy-threo-pentono-γ-lactone (XI) gave unsatisfactory results. Formation of methyl l-threo-2,3-di-O-acetyl-5-chloro-5-deoxy-4-C-hydroxymethyl-4,4′-anhydropentonate (IX) in addition to diazoketone (VIII) was observed when ester chloride (VI) was treated with an excess of diazomethane. On the basis of the observed (−)-Cotton effect in the 290 nm region of ORD and CD spectra of l-threose (IV) and d-erythrose, possibility of the presence of an open chain non-hydrated alde-hyde-form of aldotetrose in water was discussed.

Chemical Constituents of Anneslea fragrans and Their Antiausterity Activity against the PANC-1 Human Pancreatic Cancer Cell Line

“…Therefore, the α-hydroxy-γ-butyrolactone unit in 2 was concluded to be threono-1,4-lactone. The absolute configuration of the α-hydroxy lactones can be deduced by employing the axial halo-ketone rule, with the orientation of the α-hydroxy group determined from the sign of the electronic circular dichroism (ECD) spectrum Cotton effect. , According to this rule, the S (or R ) configuration at the α-carbon gives a positive (or a negative) Cotton effect at 220–230 nm. In the ECD spectrum of 2 , a negative Cotton effect was observed at 223 nm (Figure ), suggesting the R -configuration at C-3″.…”

Synthesis of anthopleurine, the alarm pheromone from Anthopleura elegantissima

“…TLC analysis of the reaction mixture showed two major products, one corresponding in Rf to the betaine and the other remaining at the origin. This polar product is probably a trimethylammonium salt, resulting from an intramolecular displacement of trimethylamine by the Ag20 9 (1.00) 18 (2.00) 25 (2.80) 4 (0.49) a Performed with a Beckman Model 120C amino acid analyzer, using citrate buffer throughout.…”

The α‐L‐Threofuranosyl‐(3′→2′)‐oligonucleotide System (‘TNA'): Synthesis and Pairing Properties

“…Preparation of the 1',2',3'-Triacylated l-Threose Derivatives 5 and 6 Starting from l-Ascorbic Acid Helvetica Chimica Acta ± Vol. 85 (2002) 4115 8 ) Reduction of the threonolactone 3 with disiamylborane to afford l-threose has been reported [17], but, in our hands, reduction of 3 with this reagent was not easily reproducible, and, therefore, DIBAL-H was chosen as the reducing agent. The reaction time in this reduction step depended the rate of addition of DIBAL-H, yet neither a faster addition nor an excess of the reducing reagent were observed to give rise to over-reduction.…”