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Hydrolysis of the enol ethers 9a and 9b gave the aldehyde 10 which cyclized in situ to the alcohols 11a and 11b via an intramolecular Prins reaction. Further regio- and stereocontrolled elaboration of the alcohols 11a and 11b afforded the lactone diol 14.

The conjugate addition of lithium diorganocuprate reagents to the enol tosylate of 1,2-cyclohexanedione has been investigated. The intermediate enolates eliminate para-toluenesulfmate ion to generate the alkylated 1,2-dicarbonyl system.

Hydrolysis of the enol ethers 9a and 9b gave the aldehyde 10 which cyclized in situ to the alcohols 11a and 11b via an intramolecular Prins reaction. Further regio- and stereocontrolled elaboration of the alcohols 11a and 11b afforded the lactone diol 14.

The conjugate addition of lithium diorganocuprate reagents to the enol tosylate of 1,2-cyclohexanedione has been investigated. The intermediate enolates eliminate para-toluenesulfmate ion to generate the alkylated 1,2-dicarbonyl system.

Relatively few carbohydrate experiments have been reported for the microscale organic laboratory curriculum despite the considerable importance of these biomolecules. This article describes an experiment that encourages discussion of carbohydrate chemistry in terms of reaction mechanisms, conformational analysis, and spectroscopy. The specific experiment involves the preparation of the bis(acetonide) of D-(+)-mannose.

The displacement reaction between sodium thiophene-3-thiolate and methyl 3-(bromomethyl)thiophene-2-carboxylate (5) gave the expected thioether 7a. Basic hydrolysis afforded the carboxylic acid 7b; conversion to the acid chloride, and treatment of the latter with stannic chloride then produced the bisthienothiepinone 1. Using analogous reactions the isomers 2-4 were also synthesized.