Synthetic studies on siphonariid polypropionates: synthesis and isomerization of the caloundrin B trioxaadamantane ring system.
(1R,3R,5R,7R,8S,9R,10S)-3,5-Diethyl-8,9,10-trimethyl-2,4,6-trioxatricyclo[3.3.1.1(3,7)]decan-1-ol (II), a model of the trioxaadamantane ring system embedded in caloundrin B, was prepared by isomerization of the thermodynamically unstable (9S)-diastereomer (I) in the presence of imidazole. Alternatively, isomerization of I with HF.py or DBU gave the hemiacetal III or its retro-Claisen ester IV, respectively, which represent structural motifs present in the closely related siphonariid polypropionates siphonarin B and baconipyrone C.
Beye
Garrison E
GE
Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon SK S7N 5C9, Canada.
Goodman
Jonathan M
JM
Ward
Dale E
DE
D000218:Adamantane / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D020650:Combinatorial Chemistry Techniques; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D011753:Pyrones / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
C539668:(1R,3R,5R,7R,8S,9R,10S)-3,5-diethyl-8,9,10-trimethyl-2,4,6-trioxatricyclo(3.3.1.13,7)decan-1-ol; D007659:Ketones; D011753:Pyrones; D013141:Spiro Compounds; C539669:caloundrin B; C448330:siphonarin B; C410203:baconipyrone C; D000218:Adamantane