Patent number: 5565345
Abstract: A process for preparing 5,6-dihydro-4-hydroxy-(S)-6-methyl-thieno[2,3-b]thiopyran-7,7-dioxide having the formula (II): ##STR1## which comprises subjecting 5,6-dihydro-4-oxo-(S)-6-methyl-thieno[2,3-b]thiopyran-7,7-dioxide having the formula (I): ##STR2## to the action of a microorganism to reduce the thienothiopyran derivative having the formula (I), and collecting 5,6-dihydro-4-hydroxy-(S)-6-methyl-thieno-[2,3-b]thiopyran-7,7-dioxide having the formula (II) from the reaction mixture, wherein said microorganism belongs to the genus selected from the group consisting of Ambrosiozyma, Arthroascus, Ashbya, Candida, Cryptococcus, Hansenula, Kluyveromyces, Lipomyces, Lodderomyces, Metschnikowia, Pachysolen, Pichia, Rhodosporidium, Rhodotorula, Saccharomyces, Saccharomycopsis, Schwanniomyces, Sporidiobolus, Spolobolomyces, Stephanoascus, Trigonopsis, Trichosporon and Wingea, according to which, a simple and effective. process for preparing 5,6-dihydro-4-hydroxy-(S)-6-methyl-thieno-[2,3-b]thiopyran-7,7-dioxide.
Type:
Grant
Filed:
January 30, 1995
Date of Patent:
October 15, 1996
Assignee:
Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
Inventors:
Yoshihiko Yasohara, Yoshiko Tari, Noboru Ueyama, Junzo Hasegawa, Satomi Takahashi