ISSN:
1434-193X
Keywords:
Caulerpa taxifolia
;
Natural products
;
Chemoselectivity
;
Epoxidation
;
Regioselectivity
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Caulerpenyne (1), the abundant sesquiterpene of the green seaweed Caulerpa taxifolia, has been epoxidized with dimethyldioxirane. The reaction proceeds with significant regioselectivity and moderate diastereoselectivity, the addition of oxygen occurring preferentially at the C(6)=C(7) double bond thereby giving (6S,7S)- and (6R,7R)-epoxycaulerpenynes 10 and 12 in an approximately 2:1 molar ratio besides a small amount of 10,11-epoxycaulerpenyne as an equimolecular diastereomeric mixture 8. The epoxides underwent rearrangement under acidic conditions; the 6,7-epoxides were easily converted into allylic alcohols, whereas the 10,11 isomers required more drastic acidic conditions and gave complex mixtures containing two diastereoisomeric 1,4-dioxanes and an enynone. The high reactivity of 6,7-epoxycaulerpenynes suggests their involvement in the biogenetic pathways of the alga.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
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