Highly diastereoselective 1,4-addition of an organocuprate to methyl alpha-D-gluco-, alpha-D-manno-, or alpha-D-galactopyranosides tethering an alpha,beta-unsaturated ester. Novel asymmetric access to beta-C-substituted butanoic acids

Carbohydrates as Synthetic Tools in Organic Chemistry

While amino acids, terpenes and alkaloids have found broad application as tools in stereoselective organic synthesis, carbohydrates have only lately been recognised as versatile starting materials for chiral auxiliaries, reagents, ligands and organocatalysts. The structural diversity of carbohydrates and the high density of functional groups offer a wide variety of opportunities for derivatization and tailoring of synthetic tools to a specific problem.

Preparation of Tertiary Amides from Carbamoyl Chlorides and Organocuprates

[reaction: see text] Reaction of carbamoyl chlorides with cyano-Gilman cuprates affords tertiary amides in good to excellent yields. The reaction is general due to the possibility of using reagents made either from organolithium or from Grignard compounds. The characterization of the main side products allowed for the suggestion of a possible mechanism.

Inositols as chiral templates: 1,4-conjugate addition to tethered cinnamic esters

The 1,4-addition of thio nucleophiles to chiro-inositols containing a cinnamyl Michael acceptor proceeded with excellent diastereochemical induction and good yields. Cleavage of the inositol auxiliary provides beta-thio hydrocinnamic acids in >99% ee's.

Monoesterification of di-O-isopropylidene and di-O-cyclohexylidene chiro-inositols

Monoesterification of D- or L-chiro-inositols protected as diacetals proceeds in excellent selectivity and yields. The metal-catalyzed, one-step reaction proceeds at room temperature under an air atmosphere and has been developed using a range of examples.