D-Ribose diethyl dithioacetal

C9H20O4S2 D-Ribose diethyl dithioacetal (DRETAC)316 CuH15C107 Tri-0-acetyl-/ -D-xylopyranosyl chloride (TACXYP)317 CuH1605 2,3,4-Tri-O-acetyl-a-D-xylopyranose (TAXYLP)318 C12H220,i -HoO 6-O-a-D-Galactopyranosyl-a.fl-D-glucopyranose, monohydrate (MELIBM03)319... 

Schmidt and Wernicke found that concentrated hydrochloric acid and a-toluenethiol, allowed to react with 2-0-benzyl-o-fucose overnight at room temperature, caused elimination of the benzyl group. It was retained however, when ethanethiol and hydrochloric acid (saturated at —15°) were employed for 0.5 hour at 0°. Kenner, Taylor and Todd converted 5-0-benzyl-D-ribose into 5-0-benzyl-D-ribose diethyl dithioacetal by the action of ethanethiol and concentrated hydrochloric acid on the sugar in dioxane at 0° during 25 minutes. Ballou and Fischer obtained an excellent yield of 2-0-benzyl-o-glycerose diethyl dithioacetal from 2-0-benzyl-o-glyc-erose, ethanethiol, and concentrated hydrochloric acid at 0° during 30 minutes. 

C15H28O4S2 336.516 Syrup. [a]o -94 (c, 1 in CHCI3). The structs. of the main isopropylidenation prods, have been confused before 1985 according to Aslani-Shotorbani et al. 2,5 3,4-Diisopropylidene 2,5 3,4-Di-0-iso-propylidene-D-ribose diethyl dithioacetal [76491-02-6]... 

Cyclohexylidene 4,5-O-Cyclohexyli-dene-D-ribose diethyl dithioacetal [99773-15-6]... 

O -Isopropylidene-a-D-x y/o -pentodialdo-1,4-furanose, P-36 0-Isopropylidene-a-D-er yzAro-pentofuranos-3-ulose oxime, P-43 O -Isopropylidene-p-D-zAreo -pentulofuranose, P-48 O -Isopropylidene-5-0 -pivaloyl-a-D-glucofuranurono-6,3-lactone, G-539 0-Isopropylidenequinide, Q-10 O -Isopropylidene-L-rhamnitol, R-7 O -Isopropylidene-L-rhamnitol, R-7 0-Isopropylidenerhamnose, 1-72 O -Isopropylidene-D-ribono-1,4-lactone, R-128 O -Isopropylidene-a-D-ribopyranose, R-138 0-Isopropylidene-p-D-ribopyranose, R-138 0-Isopropylidene-D-ribose diethyl dithioacetal, R-140 0-Isopropylidene-D-ribose diethyl dithioacetal, R-140 0-Isopropylidene-D-ribose diethyl dithioacetal, R-140 0-Isopropylideneribose, 1-73 0-Isopropylideneribose, 1-74... 

Further examples of rearrangements involving cyclic sulphonium ions have been reported. Thus 2,3,5-tri-0-methyl-4-0-toluene-/>-sulphonyl-D-ribose diethyl dithioacetal (184) and dibenzyl dithioacetal (185) gave 4- S -ethyl-2,3,5-tri-0-methyl-4-thio-L-lyxose (186) and benzyl 2,3,5-tri-0-methyl-l,4-dithio-a-L-lyxo-furanoside (187) (Scheme 46) when heated either in aqueous pyridine or with sodium iodide in acetone similar rearrangements to the 4-thiofuranosides were observed with 2,3,5-tri-0-methyl-4-0-toluene-p-sulphonyl-D-xylose and -lyxose... 

---