Chemical and microbiological remote functionalisation of (+)- and (−)-bornyl acetate

Chemical oxidation of (−)-bornyl acetate provides a mixture of 3-, 5-, and 6-oxobornyl acetate, whereas microbiological hydroxylation with cultures of Helminthosporiumsativum gives a mixture of 2,3-, 2,6-, and 2,5-bornanediols. In each case the reaction occurs preferentially at the C(5) position. Microbiological hydroxylation of (+)-bornyl acetate with H. sativum occurs almost exclusively at the C(5) position. Regiospecific hydroxylation of (+)- or (−)-bornyl acetate with cultures of Fusariumculmorum also occurs at the C(5) position but without concomitant hydrolysis of the acetoxy group.