PURPOSE: To obtain hydantocidin useful as a herbicide by hydrating a sugar derivative in the presence of manganese dioxide and a solvent, then brominating the resulting product, further spiro-cyclizing the brominated product with the use of silver cyanate or the like and subsequently removing the protective groups.

CONSTITUTION: A compound of formula I (wherein R is a protective group) is hydrated in the presence of manganese dioxide and a solvent (e.g. methylene chloride), then reacted with the use of a brominating agent (e.g. N- bromosuccinimide) to obtain a 1-bromo-1-amide compound of formula II. Subsequently, the compound of formula II is reacted with silver cyanate or silver thiocyanate in an anhydrous protic solvent (e.g. nitromethane) at 75-150°C to obtain a compound of formula II (wherein X is O or S). Further, the compound of formula III is subjected to the protection removal in the presence of a base (e.g. aqueous lithium peroxide) to obtain (+)-hydratocidin of formula IV. The compound is useful in inhibiting Echinochloa, Saccharum, Setaria viridis, Ambrosia artemisiifolia or the like.