Photocyclization of Oxo-D-fructose pentaacetate and Oxo-L-sorbose pentaacetate

Abstract

Ultraviolet irradiation of both 1,3,4,~,6-penta-o-acety~-keto-~-fructose (1) and 1,3,4,5,6-penta-o-acetyl-keto-L-sorbose (2) (epimeric at the y carbon) has been found to produce crystalline 1 (S),4(S)-diacetoxymethyl-2(S),-3(S),4-triacetoxycyclobutan-l-o1 (3), the former giving a yield of 11.6% and the latter a yield of 26.2%. Reaction is envisioned from 1,4 biradicals in the triplet state, but no other diastereoisomers resulted. The cyclic photoproduct was converted to its hexaaoetate and was also deacetylated to a hexose isomer, CleHllOe. The deacetylated material was converted to a tetra-p-toluenesulfonylate, in which all but the tertiary hydroxyl functions were derivatized. This derivative was reduced by lithium aluminum hydride to 1 (S),4(S)-dimethyl-3(S)-cyclobutanetriol. A minor photoproduct was produced in a 0.9% yield from 1. It presumably resulted from 6-hydrogen abstraction and formation of a 1,j-biradical intermediate, which underwent ring closure to meso-( 1,2,3/~,5)-2-acetoxymeth~l-1,3,4,5-tetraacetoxycyclopentan-2-ol(4).

Carbocyclische Verbindungen aus Monosacchariden. I. Umsetzungen in der glucosereihe

“…C 63,75 H 5,92% Gef. C 6337 H 6,00% (22). Rohes 22 (s. oben) wurde chromatographisch (B) gereinigt: 01, Rf (D) 0,46.…”

“…C 76,49 H 8,08% 89 (42), 43 (7). 22) Fragmentierungsversuche in Athanol ergaben das entsprechende Diathylacetal rnit Rf (C) 0,58.…”

“…Ahnliches gilt fur intramolekulare Alkylierungen, die im allgemeinen nur dann erfolgreich verlaufen, wenn weder im Ausgangsmaterial noch im Produkt der Ringschlussreaktion P-Eliminierungen auftreten konnen [ 18-2 11. In massigen Ausbeuten lassen sich Monosaccharid-Derivate auch photochemisch in Carbocyclen iiberfiihren [22], die besten Ausbeuten (56%) wurden bei der photochemischen Uberfuhrung des ungesattigten Acetals 52) in die Didesoxyinositole 6 und 7 erzielt [23] (vgl. Schema I ) .…”

Novel and Efficient Chemoenzymatic Synthesis of D‐Glucose 6‐Phosphate and Molecular Modeling Studies on the Selective Biocatalysis

“…Lardy and Fischer11 reported a 3‐step protocol for the synthesis of G‐6‐P starting with 1,2,3,4‐tetra‐ O ‐acetyl‐β‐ D ‐glucopyranose (TAG). However, synthesis of the key starting material TAG is not straightforward and requires several protection‐deprotection steps 12. Other chemical methods for the preparation of G‐6‐P describes the phosphorylation of glucose by phosphorus oxychloride,13 phosphorus pentoxide, or polyphosphoric acid 14.…”

Chiral Synthesis of (R)-(-)(5Z)-4-Hydroxy-5-tetradecenoic Acid-4-lactone

“…The potential of 4 as chiral synthon is enhanced by the fact that catalytic hydrogenation of similar systems such as 3-deoxy-l,2:5,6-di-0-isopropylidene-a-D-glucose-3-ene occurs stereoselectively at the less hindered face, as dem onstrated by Weygand and Wolz [30]. Sun and Fraser-Reid [31] have described the prep aration of this m aterial and Nakanishi et al [32] have prepared it from l,2:5,6-di-0-isopropylidene-3-0-/?-toluensulfonyl-a-D-glucopiranose [33], by a similar route. Brown and Jones [34] have prepared 4 in poor yield from the 3-tosyl precursor by treat ment with sodium methoxide in dry m ethanol at room tem perature.…”