Hexitol Anhydrides.¹ The Structures of the Anhydromannitols of Brigl and Grüner.² The Structure of Isomannide

(3R,3aR,6R,6aR)-Hexahydrofuro[3,2-b]furan-3,6-diyl dibenzoate

“…For oxidative processes mediated by transition of oxospecies, see ;Piccialli, D'Errico et al (2013); Piccialli et al (2012). For the synthesis of the title compound, see : Hockett et al (1946).…”

“…Treatment of the latter with benzoyl chloride in pyridine for 16 h, followed by reaction with catalytic amounts of p-toluenesulfonic acid in 1,1,2,2-tetrachloroethane at reflux (Hockett et al, 1946) led to title compound as an amorphous white powder, after chromatography (CHCl 3 to CHCl 3 -MeOH, 95:5). The whole process consists of a double migration of the primary benzoates to the adjacent alcoholic functions followed by double water elimination and bis-cyclization (C1/C4 and C3/C6 ether ring closure).…”

(3S,3aS,6R,6aR)-2-Oxohexahydrofuro[3,2-b]furan-3,6-diyl dibenzoate

“…For the catalytic use of chlorochromatoperiodate, see: Piccialli, D'Errico et al (2013); Piccialli et al (2012). For the synthesis of the precursor, see: Hockett et al (1946).…”

Controlled tosylation of 1,4:3,6-dianhydro-D-mannitol and -D-sorbitol

“…Among such methods, tosylation of diols I and II seems the most available and facile (see, for instance, [6,7]). This reaction is accomplished by the action on the corresponding dianhydrohexitol of toluenesulfonyl chloride in dry pyridine under cooling or at room temperature.…”

“…The products formed at the 1 : 1 and 1 : 2 reagent ratios and detected by TLC, were isolated by column chromatography and identified as 2-tosyl-1,4 : 3,6-dianhydro-D-sorbitol (VI), 5-tosyl-1,4 : 3,6-dianhydro-D-sorbitol (VII), and 2,5-ditosyl-1,4 : 3,6-dianhydro-D-sorbitol (VIII). The structural assessment of monotosylates VI and VII and ditosylate VIII was performed by the coincidence of their melting points with published data [6,7]. At the above reagent ratios, along with ditosylate VIII, monotosylate VII is formed, i.e.…”