DOUBLE ASYMMETRIC DIHYDROXYLATION OF 1,5-HEXADIENE

Double asymmetric dihydroxylation of 1,5-hexadiene gave in one step a mixture of the d,l/meso tetrols 6 in a ratio of 3.4:1. From this ratio a facial selectivity of 6.65:1 for each double bond can be calculated . As a consequence of the double reaction the d/l ratio can be estimat ed to be 44:1. Compound 6 served then as starting material for the pre paration of the bis-epoxide 12 and the 2,5-dihydroxyhexane (13). While the separation of the diastereomers was not possible so far, this rou te for the preparation of 6, 12 and 13 might still be useful because i t is very short and products derived from them might allow the crucial separation.