Abstract: The present invention provides: industrially desirable and novel optically-active cyclopentenone derivatives; and a novel industrial manufacturing method. The novel optically-active cyclopentenone derivatives and method for manufacturing the same are, respectively: an intermediate for industrially desirable and novel prostaglandin derivatives and the like; and a method for manufacturing the same. It is expected that the present invention will be commercialized and industrialized.

Abstract: The present invention provides: industrially desirable and novel optically-active cyclopentenone derivatives; and a novel industrial manufacturing method. The novel optically-active cyclopentenone derivatives and method for manufacturing the same are, respectively: an intermediate for industrially desirable and novel prostaglandin derivatives and the like; and a method for manufacturing the same. It is expected that the present invention will be commercialized and industrialized.

Abstract: [Problem] The present invention provides an industrially-preferable, cost-efficient, low-cost production method for 4-hydroxy-2-hydroxymethyl-2-cyclopenten-1-one (a compound represented by formula (I)) useful as a medicine, an agricultural chemical, or a raw material or intermediate of a medicine, an agricultural chemical, or the like. [Solution] According to the present invention, this compound represented by formula (I) is produced by subjecting an easily available compound represented by formula (II) (tri-O-acetyl-D-glucal) to a heating reaction in pressurized water.

Abstract: [Problem] The present invention provides an industrially-preferable, cost-efficient, low-cost production method for 4-hydroxy-2-hydroxymethyl-2-cyclopenten-1-one (a compound represented by formula (I)) useful as a medicine, an agricultural chemical, or a raw material or intermediate of a medicine, an agricultural chemical, or the like. [Solution] According to the present invention, this compound represented by formula (I) is produced by subjecting an easily available compound represented by formula (II) (tri-O-acetyl-D-glucal) to a heating reaction in pressurized water.

Abstract: An automatic disc selection type reproducing apparatus comprises a disc accommodating mechanism having disc accommodating portions for accommodating discs, and a reproducer part provided below and movable along the disc accommodating mechanism. The disc accommodating mechanism is substantially arranged horizontally, and the discs are accommodated within the disc accommodating portions in a vertical state where a disc surface of one disc opposes a disc surface of an adjacent disc. The reproducer part moves and stops at a position opposing a disc which is designated by designating an address of the disc accommodating portion which accommodates this disc. The reproducer part has a disc carrying mechanism for carrying the disc which assumes the vertical state, upwardly and downwardly between the disc accommodating mechanism and the reproducer part, while supporting a lower portion of an outer peripheral edge of the disc.