Chemoenzymatic synthesis of glycosyl-deoxyinositol derivatives. First example of a fagopyritol β-analogue containing an aminoinositol unit

Achievements, Challenges, and Scope of Thirty Years of Work on the Biotransformation of Arenes and Their Synthetic Applications

“…The conjugation by traditional trichloroacemidate coupling delivered the challenging pseudodimeric carbohydrates 78 and 79 (Scheme 20). [86] The starting material 75 was easily obtained by azide opening of the epoxide prepared from bromodiol 1 b .…”

Chemoenzymatic Synthesis of Inositols, Conduritols, and Cyclitol Analogues

“…More recently, the Gonzalez group employed the easily accessible azidoconduritiol 249 (Scheme ). Azidoconduritol 249 was coupled with trichloroacetimidate 250 to form β-glycoside 251 in 92% yield and was further converted to β- d -galactopyranosyl-(1′,1)-conduramine F-4 252 in 80% yield by Staudinger reaction followed by global deprotection . Alternatively, dihydroxylation of 251 with RuCl 3 /NaIO 4 gave 253 in 91% yield, and this material was converted, after reduction of the azido group and deprotection, to β- d -galactopyranosyl-(1′,3)-4-amino-4-deoxy- l - chiro -inositol 254 .…”

“…73 Reaction of 92 with singlet oxygen followed by reduction with thiourea gave meso-2,3-di-O-isopropylidene conduritol A (93), which was subjected to desymmetrization with Pseudomonas cepacia lipase (Amano P-30) in the presence of isopropenyl acetate to furnish the monoacateate (À)-94, previously used by Johnson for the synthesis of both enantiomers of conduritol C (see Scheme 14). Reaction of 94 with phthalimide under Mitsunobu conditions afforded 275, which was fully deprotected to provide (À)-conduramine C-1 (110). Its enantiomer was prepared by protection of 94 by silylation of the hydroxy group, deacetylation to 276, and the analogous amination protocol to furnish (þ)-conduramine C-1 (ent-110).…”

Chemoenzymatic Synthesis of Hygromycin Aminocyclitol Moiety and its C2 Epimer

“…Aminocyclitols have been preferred targets in chemoenzymatic synthesis. In particular, the dioxygenase catalyzed oxidation of aromatics have resulted in a very efficient approach to optically pure aminoinositols, conduritols, as well as their deoxygenated analogues and conjugates . Initial efforts of Hudlicky et al since the early nineties of the last century have developed into a full stereodivergent strategy that has been exploited around the world to render a wide diversity of this nitrogen containing polyols .…”