Synthesis of Chiral Five-, Six-, and Seven-Membered Heterocycles from (S)-3-Hydroxy-γ-butyrolactone

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-g gamma-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.