Stereoselective trans-dihydroxylation of terpinen-4-ol:: synthesis of some stereoisomers of p-menthane-1,2,4-triol

A high level of trans-stereoselectivity in the dihydroxylation of the homoallylic alcohol, terpinen-4-ol 1 (R=H) has been achieved. Thus, the enantiomeric triols 2a and 2b were separately synthesized in high yield and with high stereoselectivity by trans-dihydroxylation of the enantiomeric (4S)-terpinen-4-ol 1a (R = H), and (4R)-terpinen-4-ol 1b (R=H), respectively, using hydrogen peroxide as oxidant and V2O5; as catalyst. In the same way, the enantiomeric triols 3a and 3b were obtained from the enantiomeric (4S)-terpinen-4-yl tosylate 1a (R=tosyl) and (4R)-terpinen-4-yl tosylate 1b (R=tosyl), respectively. (C) 2002 Elsevier Science Ltd. All rights reserved.