PROBLEM TO BE SOLVED: To provide a method of producing single-isomer benzoprostacyclin derivatives including beraprost and derivatives thereof.SOLUTION: A production method comprises reacting an aldehyde of the formula in the figure with a compound of the formula in the figure having a chiral purity greater than 95%, and reducing the product compound being carbonyl and deprotecting secondary alcohol. [Z' is alkyl-COOR； COORis a protecting group or the like； Ris a silyl hydroxy protecting group； and Rand Rare each independently H or the like.]SELECTED DRAWING: Figure 1【課題】ベラプロスト及びその誘導体を含む単一異性ベンゾプロスタサイクリン誘導体の製造方法の提供。【解決手段】上記式のアルデヒドを、９５％を超えるキラル純度を有する下記式の化合物と反応させ、形成化合物のカルボニルを還元し、第二級アルコールを脱保護する製造方法。［Ｚ’はアルキル－ＣＯＯＲ１２；ＣＯＯＲ１２は保護基等；Ｒ２ａはシリルヒドロキシ保護基；Ｒ４及びＲ５は各々独立にＨ等］【選択図】図１
