Inositol 2,3-anhydro-aZZo

An unequivocal synthesis of the racemate of LXXIV was achieved by treating 5,6-anhydro-aZZo-inositol with sodium methoxide7 (see p. 183). The pentaacetate of LXXIV has the same infrared spectrum as the pentaacetate of (+)-ononitol, and hence the ononitols are the 4-0-methyl- ra/o-inositols. 

It should be more convenient to prepare the Dirpentol by hydrogenolysis of meso-2,3-anhydro-aZZo-inositol (36) and to prepare the (- -) or (—) pentols by hydrogenolysis of suitable forms of 1,2-anhydro-aZZo-inositol (37). In the latter reaction, ZaZo-quercitol would also be formed. 

Anhydro and 1,4-anhydroinositols are not known, but 1,2-anhy-droinositols are readily prepared by two methods (a) the action of bases on tosyl derivatives in which an adjacent hydroxyl group is frans-situated, and (b) treatment of cyclohexenetetrols with peracids. The former method has been used by Angyal and coworkers,7 149 the latter by Nakajima and coworkers.34 As a result of their work, six out of the ten possible diastereo-meric anhydrides are now known. On p. 168, the preparation of (+)-l,2-anhydro-3,4 5,6-di-O-isopropylidene-aZZo-inositol (LXII) from the mono-tosyl derivative of di-O-isopropylidene-feyo-inositol has already been mentioned careful, acidic hydrolysis of LXII gives (+)-l,2-anhydro-oZta-inositol (XCIX), the most readily available of the anhydroinositols.7 Similarly, the diisopropylidene acetal of 1-O-tosyl-epf-inositol gives 5,6-an-hydro-aZZo-inositol (CIII).7 The trans-1,2-di-0-tosyl compounds react in... 

Only one example is available of the use of a preformed true anhydro-inositol for inosamine synthesis (+)-l, 2-anhydro-3,4 5,6-di-0-isopropyl-idene-aZZo-inositol (CXXVII) yields (-j-)-neo-inosamine-l (CXXVIII) and Zero-inosamine-3 (/ewo-inosamine-o, CXXIX) on ammonolysis and hydrolysis.214 However, the epoxide CXXX and its pentaacetate CXXX (see below) have been treated with ammonia and with a variety of primary and... 

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