
TY  - JOUR
A1  - Bourke, DG 
A1  - Collins, DJ 
A1  - Hibberd, AI 
A1  - Mcleod, MD 
T1  - Enolic Ortho Esters. VI. A New 'Pyranose&#8594;Cyclohexane' Transformation via 1,6-Dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-<I>xylo</I>-hex-5-enopyranose
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1996
VL  - 49
IS  - 3
SP  - 425
EP  - 434
KW  - 
UR  - https://doi.org/10.1071/CH9960425 
N2  - Hydrolysis of methyl 6-chloro-6-deoxy-2,3,4-tri-O-methyl-&#945;-D-glucopyranoside (19b) and Swern oxidation of the resulting anomeric hemiacetals (20) gave 6-chloro-6-deoxy-2,3,4-tri-O-methyl-D-glucono-1,5-lactone (21), treatment of which with 1,2-bis( trimethylsilyloxy )ethane in the presence of trimethylsilyl trifluoromethanesulfonate gave 6-chloro-1,6-dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-glucopyranose (23a). Conversion of (23a) into the corresponding 6-iodo compound (23b) and treatment of this with 1,8-diazabicyclo[5.4.0]undec-7-ene afforded the enolic ortho ester 1,6-dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-xylo-hex-5-enopyranose (26). Reaction of (26) with methylmagnesium iodide, or with titanium tetrachloride, gave (1R,6S,7R,8R,9S)-7,8,9-trimethoxy-6-methyl-2,5-dioxabicyclo[4.3.1]decan-1-ol (34), or (2S,3R,4R)-5,5-ethylenedioxy-2,3,4-trimethoxycyclohexanone (28), respectively. 
ER  -

