Barium manganate diols

Selective oxidation. The diol 1 is oxidized to the lactone 3 (cinnamolide) in 55% yield by Collins reagent. The same oxidation with AgiCOi/Celite (Fetizon reagent) is essentially quantitative. The cheaper barium manganate is equally effective, and has the advantage that the intermediate lactol 2 can also be obtained if desired. 

The selective oxidation of diols in which one or both hydroxy groups are allylic has been reported on a number of occasions. Reagents which have proved use for this include silver carbonate on Celite, barium manganate/ and manganese dioxide, as illustrated in equations (29)-(31). 

The oxidation of diols having alcoholic groups of the same nature, for example, both alcoholic groups are primary, secondary, allylic, or benzylic, is usually carried out at both groups to yield dialdehydes [832] or diketones [552], Such reactions are achieved by chromium trioxide [582], barium manganate [832], dimethyl sulfoxide activated with acetic anhydride [1013], and others (equations 284 and 285). 

M.C. Bagley, Z. lin, D.J. Philips, A.E. Craham, Barium manganate in microwave-assisted oxidation reactions synthesis of lactones by oxidative cyctization of diols. Tetrahedron Lett. 50 (2009) 6823-6825. 

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