David R. Hicks

Synthesis of one enantiomer, the other enantiomer, and a mixture of both enantiomers of frontalin from a derivative of methyl-α-D-glucopyranoside

The ketone (1), derivable from methyl-α-D-glucopyranoside in four steps, may be converted into one enantiomer, the other enantiomer, or a mixture of both enantiomers of frontalin in 13% overall yield.

Annulated sugars: Formation and reactions of some cyclobutanohexopyranosides

Abstract The preparation of cyclobutanopyranosides by [2 + 2] photoadditions to methyl 2,3-dideoxy-2-C-methyl-α- d -glycero-hex-2-enopyranosid-4-ulose has been explored. Vinyl acetate adds readily, giving a mixture of diastereomers in good yield. Attempts to deacetylate the photoadduct causes gross decomposition. However, the addition of excess of methyl-lithium converts the carbonyl group into a tertiary alcohol and cleaves the acetate. Attempts to deoxygenate selectively the secondary hydroxyl of the resulting diol were unsuccessful. With ethylene, the photoaddition requires several days and the risk of photodecomposition is high. Some transformations of the photoadducts are described.

The Photoaddition of Aldehydes to Enones: A Direct Route to 1,4-Diketones

Abstract Recent work in this2 and other3 laboratories has shown that the photochemically-induced addition of oxy-carbinyl species to enones provides a simple and effective method of carbon-carbon bond formation. Thus addition of alcohols2C,3,4 and acetals2a to enones (e. g. 1 or 4) affords keto-alcohols (e. g. 2 or 5) and keto-ketals (e. g. 6), the synthetic value of which are enhanced by the fact that the functionalities are conveniently differentiated, thereby facilitating selective manipulation.5

Acid versus base hydrolysis of a disulphonylated hexitol. 1,4,3,6-Dianhydro-D-iditol (D-isoidide)versus 2,3:4,5-dianhydro-D-iditol

Whereas acid hydrolysis of 3,4-di-O-methylsulphonyl-D-mannitol (2) produces 1,4-anhydro-3-O-methylsulphonyl-D-talitol (4) and thereafter 1,4:3,6-dianhydro-D-iditol (3), base hydrolysis of the ester (2) gives isomeric 2,3:4,5-dianhydro-D-iditol (8) exclusively.