Synthesis of chiral five-, six-, and seven-membered heterocycles from (S)-3-hydroxy-γ-butyrolactone

摘要

Chiral small molecules such as amino alcohols and their heterocyclic derivatives are useful building blocks for asymmetric synthesis and the preparation of biologically active compounds. Using a common starting material derived from carbohydrate, the (S)-3-hydroxy - butyrolactone, we have synthesized several five-, six-, and seven-membered nitrogen-containing chiral heterocycles. These include (S)-3-benzyloxypyrrolidine, a protected 6-substituted morpholin-3-one and its homologous 1,4-oxazepan-3-one, and 6-trityloxymethyl tetrahydro-1,3-oxazine-2-thiones. These chiral small heterocycles were synthesized from the lactone via efficient cyclization reactions. Their syntheses and characterization are reported here.