title: Studies toward the synthesis of the shark repellent pavoninin-5.
abstract: Sharks are the most dangerous predators of people in the sea, resulting in people being mauled and killed each year. A shark repellent could help to diminish this danger. The aglycone of the shark repellent pavoninin-5, (25R)-cholest-5-en-3beta,15alpha,26-triol (5a), was synthesized from diosgenin (9). Removing mercury from the Clemmensen reduction of 9 gave a higher yield of (25R)-cholest-5-en-3beta,16beta,26-triol, 10a, and was also more environmentally friendly. Attempted methods for the transposition of the C-16beta hydroxyl to the 15alpha position are described. A successful method for this transposition via the 15alpha-hydroxy-16-ketone, 8a, using the Barton deoxygenation reaction on the 16-alcohol 14b, is reported.
authors.affiliation: Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122-2585, USA. john.r.williams@temple.edu
authors.forename: John R
authors.initials: JR
authors.lastname: Williams
authors.forename: Deping
authors.initials: D
authors.lastname: Chai
authors.forename: Hua
authors.initials: H
authors.lastname: Gong
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Dominic
authors.initials: D
authors.lastname: Wright
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D000818:Animals; D002784:Cholesterol / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D012754:Sharks
chemical_list: C479631:cholest-5-en-3,15,26-triol; D002784:Cholesterol; D000117:Acetylglucosamine