Various kinds of nonbranched and methyl-branched 6-deoxyh,ex-5-enopyranoside derivatives were prepared from 6-bromo-6-deoxy or 6-O-p-tolylsulfonylhexopyranoside in a ·one-pot procedure by a successive treatment with iodide anion and 1,8-diazabicyclo[5.4.0]undec-7-ene in dimethyl sulfoxide. The scope and limitations of this reaction have become apparent by observing the reactions of 18 substrates. The yields of altropyranoside and 2-deoxyribo-hexopyranoside derivatives were high, except for the 2,3-anhydropyranoside derivative. Methylbranched 6-deoxyhex-5-enopyranoside derivatives were also obtained in practical yields.6-Deoxyhex-5-enopyranosides are very useful precursors in biologically important natural-product synthesis, such as 6-deoxy-L-hexose!) and the cyclitol derivative?} In general, 6-deoxyhex-5-enopyranosides have been synthesized by treating the corresponding 6-bromo derivative with AgF/pyridine,3} 1,or NaH/N,Ndimethylformamide (DMF).5) These methods, however, have some limitations, such as displacement reactions with fluorine, acyl migration reaction, and deacylation. At the beginning of our 5-enopyranosides syntheses, we used DBU/CH 3 CN as a useful synthetic method; however, it required a longer reaction time and gave side products in many cases. Furthermore, this method did not work well in the case of methyl-branched series. Regarding another type of elimination reaction, S. Hannesian has reported on the use of DBU/DMSO in the synthesis of carbohydrate derivatives containing the vinylic thioether group by eliminating the mesyl group. In that report, the elimination with DBU/DMSO under heating for 2.5 h at 85°C gave the corresponding 2,3-unsaturated derivative in good yield.6 ) The strong base ability of DBU/DMSO probably suggests the intermediacy of the DMSO carbo anion in DMSO. If we can use DBU/DMSO methods in the syntheses of hex-5-enopyranosides, the elimination reaction may progress faster than DBU/CH 3 CN. In order to contribute to the development of such 6-deoxyhex-5-enopyranosides syntheses, the authors examined DBU/DMSO methods and communicated a convenient and general method for synthesizing 6-deoxyhex-5-enopyranosides from the corresponding 6-bromo-6-deoxy-or 6-O-p-tolylsulfonylhexopyranosides in a one-pot procedure by a successive treatment with the iodide anion, DBU, and molecular sieves (MS) 4A in dimethyl sulfoxide (DMSO), instead of CH 3 CN. This paper describes details concerning the communication 7 } as well as the scope and limitations of the above method by using 18 substrates, i.e., nonbranched (1, 5, 8, 12, 14, 16, 18, 20, 22, 25, and 28) and a methyl-branched series (32, 34, 36, 38, 40, 42, and 44) (Chart 1, Figs.

The title compound was synthesized from D-glucose as a key intermediate of DInositol-I,4,5-triphosphate synthesis without doing any optical resolution by utilizing C 2 symmetry.Since the discovery of the role of D-myo-inositol 1,4,5-triphosphate( IP 3 ,1) as an intracellular second messenger for calcium mobilization,I) a great biological interest in IP) has been increased In order to explore the biochemical processes, a simple, general, and efficient methodology for chemical syntheses of IP 3 , 1 and its derivatives is required. Up to date, for the synthesis of IP 3 and its derivatives, myoinositol has been mainly used as a starting material. But previous methods have required a optical resolution. Here we now report a new strategy for synthesizing the partially-protected key intermediate,was prepared from Dglucose in 56 % yield (3 steps) (Scheme 1 ). 6-Deoxyhex-5-enopyranoside derivative(4) was synthesized by treatment of 3 with sodium iodide, tetrabutylammonium iodide, 1,8-diazabicycIo[5,4,O]undec-7-ene(DBU) and molecular sieves 4A in dimethyl sulfoxide(DMSO) at 80-110°C ( one pot reaction,3) 63% yield). Detosylation of compound 4 followed by protection with benzyl group gave methyI2-0-benzyl-6-deoxy-3,4-di-Omethoxymethyl-a-D-xylo-hex-5-enopyranoside (5) in 87% yield. Ferrier reaction 4) of 5 gave partiallyprotected 2,3,4,5-tetrahydroxycyclohexanone derivative(6) which was treated with acetic anhydride in pyridine to give the corresponding enone derivative (7) in 77% yield(2 steps). Reduction of 7 with sodium borohydridecelium chloride in ethanol, followed by benzylation of hydroxyl group gave protected cyclohexenol derivative[8: NMR (CDCI); f> 3.79 and 4.17 ppm ( each dd, 4H, A2B2, J=5.1, 2.4 Hz), 5.73 (s, 2H)] in 89% yield (2 steps). Oxidation of compound 8, which has C 2 symmetry axis, with osmium tetroxide gave partially protected myo-inositol derivative(9) in 83% yield. Regioselective protection of vicinal hydroxyl group by use oftris butyl stanyl oxide and methoxymethyl chloride, followed by benzylation of remaining hydroxyl group gave full OH

C-Methylcyclitols such as laminitol and mitilitol are characteristic components of various algaes 1) and, in general, can be prepared by introduction of methyl-branch into the corresponding cyclitol. However, this method has difficulties in availability of required starting cyclitols, selective protection of the desired hydroxyl group, and stereoselective introduction of methyl-branch. In order to overcome these difficulties, we examined preparation of methyl-branched cyclitol derivatives using Ferrier's method) This communication describes a convenient synthesis of protected novel methyl-branched 2,3,4,S-tetrahydroxycyclohexanone derivatives (9-12, 17, 18, and 21) from the corresponding branched-chain 6-deoxyhex-S-enopyranosides (5-8, 15, 16, and 20). Key intermediates (5-8, 15, 16, and 20) 3) were newly prepared in one-pot procedure from corresponding 6-bromo-6deoxy-(1-4, 13, and 14) 4) or 6-p-tolylsulfonylhexopyranoside 19 4) by successive treatment with iodide anion and l,8-diazabicyclo(S,4,O)undec-7-ene (DBU) in dimethyl sulfoxide (DMSO) at 80-120•C.5) The favorable procedure for this elimination reaction were as follows: A

Die durch Reaktion des Stilbens (I) mit den 6‐substituierten Triazinen (II) gewonnee nen Aufheller (III) reagieren mit Baumwolle in Gegenwart von Soda zu fluoreszierenden Stoffen, von denen sich der Aufheller nicht mit heißem Pyridin oder Dimethylformamid entfernen läßt. Zur Fixierung der Aufheller auf Nylon oder Seide ist die Anwesenheit von Essigsäure erforderlich.

Syntheses of 6-Deoxyhex-5-enopyranosides from 6-Bromo-6-deoxy-or 6-O-p-Tolylsulfonylhexopyranosides by the Use of DBU in DMSO. -Pyranosides of type (I), (III), (V), and (VII) are efficiently transformed to the corresponding enopyranosides. In the case of anhydropyranosides, e.g. (IX), side reactions are observed. -(SATO, K.; KUBO, N.; TAKADA, R.; SAKUMA, S.; Bull. Chem.