Wilcox and Gaudino

This notation blends smoothly with the plus-minus notation to indicate sequences of reactions or multifunctional reagents. In the simple, hypothetical transformation in Scheme 20, dibromomethane might serve as a reagent for the synthon (5). A slash (/) separates the two symbols (-/ ) to indicate that (5) will behave separately as a nucleophilic site and a radical site, rather than as a radical anion. The more rigorous notation of Seebach avoids this confusion. Related transformations have actually been executed by Wilcox and Gaudino.76... 

In the pioneering work by Wilcox and Gaudino, a straightforward route to the carbocyclic analogue of D-fructofuranose, 64, and its 6-phosphate derivative was delineated [14a,b]. As shown in Scheme 9, the first move consisted of Wittig olefination of benzyl-protected arabinose 60 with carboxy-tert-butylmethylene triphenyl phosphorane to deliver unsaturated ester 61, which was then cleverly elaborated into dibromide 62 via a reaction cascade encompassing Swem oxidation of the secondary OH, ester hydrolysis, diastereoselective addition of dibromomethyl lithium, and carboxylic acid methylation. 

As a whole, this procedure encompasses 11 steps from D-arabinose with a 45% global yield, as compared to an 18% yield, 12-step historical synthesis by Wilcox and Gaudino. 

C. S. Wilcox and J. J. Gaudino, New approaches to enzyme regulators. Synthesis and en-zymological activity of carbocyclic analogues of D-fructofuranose and D-fructofuranose... 

J. J. Gaudino and C. S. Wilcox, A concise approach to enantiomerically pure carbocyclic robose analogues. Synthesis of (4S, 5R, 6R, 7R)-7-(hydroxymethyl)spiro[2.4Jheptane-4,5,6-triol-... 

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