Chemoenzymatic synthesis of carbasugars from iodobenzene.
The versatile enantiopure cis-dihydrodiol metabolite 1, formed by bacterial metabolism of iodobenzene, has been used for the synthesis of the pyranose carbasugars (pseudosugars) carba-beta-D-altropyranose 2, carba-alpha-L-galactopyranose 3, carba-beta-D-idopyranose 4 and carba-beta-L-glucopyranose 5. Substitution of the iodine atom by a carbomethoxy group, stereoselective catalytic hydrogenation of an alpha,beta-unsaturated ester, and regioselective inversion of one or two allylic chiral centres are the key steps used in the synthesis of carbasugars 2-5. The relative and absolute configurations of compounds 2-5 were established by a combination of stereochemical correlation, X-ray crystallography and 1H-NMR spectroscopy.
Boyd
Derek R
DR
Centre for Theory and Application of Catalysis, School of Chemistry, The Queen's University of Belfast, Belfast, UKBT9 5AG.
Sharma
Narain D
ND
Llamas
Nuria M
NM
Malone
John F
JF
O'Dowd
Colin R
CR
Allen
Christopher C R
CC
D002241:Carbohydrates / Q000096:biosynthesis*; D018360:Crystallography, X-Ray; D007462:Iodobenzenes / Q000737:chemistry*
D002241:Carbohydrates; D007462:Iodobenzenes; C031905:iodobenzene