中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | methyl 6-bromo-6-deoxy-2,3,4-tri-O-methyl-6-phenyl-α-D-glucopyranoside | 213968-26-4 | C16H23BrO5 | 375.26 |
—— | 1-O-acetyl-6-bromo-6-deoxy-2,3,4-tri-O-methyl-6-phenyl-α-D-glucopyranose | 213968-27-5 | C17H23BrO6 | 403.27 |
—— | methyl 2,3,4-tri-O-methyl-6-C-phenyl-α-D-glucopyranoside | 213968-24-2 | C16H24O6 | 312.363 |
—— | methyl 2,3,4-tri-O-methyl-6-O-methylsulfonyl-6-C-phenyl-α-D-glucopyranoside | 213968-25-3 | C17H26O8S | 390.455 |
The known aldehyde methyl 2,3,4-tri-O-methyl-α-D-gluco-hexodialdo-1,5-pyranoside (9) was converted in eight steps into the 6-phenyl glucose-derived enolic ortho ester (Z)-1,6-dideoxy-1,1-ethylenedioxy- 2,3,4-tri-O-methyl-6-phenyl-D-xylo-hex-5-enopyranose (22), the geometry of which was established by a single-crystal X-ray study. Treatment of the 6-phenyl enolic ortho ester (22) with titanium tetrachloride at –78° effected clean rearrangement into (2R/S,4R,5R,6S)-3,3-ethylenedioxy-4,5,6-trimethoxy-2-phenylcyclohexanone (26). Reaction of (22) with methylmagnesium iodide gave (1R,2S,4R,5S,6S)-3,3-ethylenedioxy-4,5,6-trimethoxy-1-methyl-2-phenylcyclohexanol (24), the structure and stereochemistry of which were established by an X-ray study. Reaction of (22) with phenylmagnesium bromide gave (25), the 1-phenyl analogue of (24). The firmly established structure of (24) led to proof both chemically and by X-ray means that the product from reaction of 1,6-dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-xylo-hex-5-enopyranose (5) with methylmagnesium iodide has the hydroxy acetal structure (7) rather than the originally assigned hemiacetal structure (3).