| 摘要 |
<p>PURPOSE:To simply obtain the title compound both in high stereoselectivity and high yield by cyclization of a N-benzoyl-delta,epsilon-unsaturated amide compound with iodine followed by introduction of a protective group and then debenzoylation. CONSTITUTION:Firstly, a reaction is made between a compound of formula I (R1 is protective group for OH; pH is phenyl) and iodine in a solvent such as water-THF at 0-50 deg.C into a compound of formula II. Then the amino group of this compound is protected by introduction of a protective group to form a compound of formula III (R2 is protective group for amino group). Thence, using e.g. potassium carbonate, this compound is put to debenzoylation in a solvent such as methanol at 10-30 deg.C, or debenzoylation along with the elimination of R1, or debenzoylation followed by protecting the OH with the same protective group as R1, thus obtaining the objective compound of formula IV. The present compound is also useful as an asymmetric element in asymmetric synthesis, or as an intermediate for synthesizing a kind of amino acid, etc.</p> |
