76-78-8Relevant articles and documents
Hydrolysis of 1,4,6-trioxaspiro[4.5]decanes to δ-lactones using 2,3- dichloro-5,6-dicyanobenzoquinone in aqueous acetone
Vasudevan,Watt
, p. 361 - 364 (1994)
A selective hydrolysis of 1,4,6-trioxaspiro[4.5]decane orthoesters by 2,3- dichloro-5,6-dicyanoquinone (DDQ) in aqueous acetone in the presence of other acid-sensitive ketals is suggested to involve the formation of a charge- transfer complex followed by hydrolysis. A hydride-transfer mechanism for this oxidation was excluded.
Total Synthesis of (+)-Quassin
Shing, Tony K. M.,Jiang, Qin
, p. 7059 - 7069 (2007/10/03)
A total synthesis of (+)-quassin from naturally occurring (S)-(+)-carvone is described. The total number of steps was 28, and the overall yield was about 2.6%. The synthetic strategy for the construction of the tetracyclic carbon framework was based on a C→ABC→ABCD ring annulation sequence, involving an aldol reaction, an intramolecular Diels - Alder reaction, and an intramolecular acylation as the key steps. Subsequent functionalization of ring A and ring C then afforded the target (+)-quassin.
Total synthesis of d,l-quassin
Stojanac, Nada,Valenta, Zdenek
, p. 853 - 855 (2007/10/02)
The completion of the total synthesis of d,l-quassin 1 is described.Key steps are a facile intramolecular acylation of a protected cyanohydrin carbanion (4 -> 5), a selective deprotonation with trioctyl methyl ammonium hydroxide leading to the removal of HCN from 8, and the unusual sequence 5 -> 12 in which the ring C enol ether of 5 is converted selectively into ring C diosphenol of 12. Key words: quassin, synthesis, selective base, diophenols, acylation.