N-ALKOXY ANALOGS OF 3,4,5-TRIHYDROXYPIPERIDINE

Two practical procedures are described for the synthesis of the N-alko xy analogues of 3,4,5-trihydroxypiperidine. The key feature of these m ethods is the intramolecular N-cyclization of hydroxylamine derivative s which are readily obtained from the reduction of the corresponding o ximes. One method is to reductively hydroxyaminate an aldehyde group i n the presence of a primary tosylated alcohol which is subsequently cy clized in situ upon neutralization. The intramolecular Mitsunobu coupl ing of a hydroxylamine with a primary alcohol proved useful for the pr eparation of compounds which contained the trans diol structure.