Common synthetic strategy for optically active cyclic terpenoids having a 1,1,5-trimethyl-trans-decalin nucleus: syntheses of (+)-acuminolide, (−)-spongianolide A, and (+)-scalarenedial

Recent Advances in the Syntheses of Decalin Type Natural Products

“…Acid treatment of 116 gave the (+)-hydroxy ketone (118) (89% yield) and (R,R)-cycloheptane 1,2-diol (87% yield). The physical data of (+)-118 was identical to those of the previously reported (+)-(8aR)-11845 On the other hand, acid treatment of 117 gave the (-)-hydroxy ketone (118) (97% yield) and(R,R)-cycloheptane 1,2-diol (97% yield). The physical data of (-)-118 was identical to those of the previously reported (-)-(8aS)-11845 and the absolute configuration of the present 117 was determined to…”

Total synthesis of two 12-nordrimanes and the pharmacological active sesquiterpene hydroquinone yahazunol

“…According to the procedure of Furuichi et al 9 the racemate of (G)-8-oxo-12-nordrimanic acid methyl ester ((G)-1) was transformed with (2S,3S)-1,4-di-O-benzylthreitol to the diastereomeric mixture of dioxolanes. Hydrogenolytic splitting of the benzyl groups led to the diols, which could be separated by silica gel MPLC.…”

“…9 The racemate of (G)-1 reacted with (2R,3R)-2,3-butanediol to the both diastereomers which were reduced with DIBAH to the diastereomeric alcohols. These could be separated by silica gel MPLC.…”

Synthetic paths towards scalaranes: Assembling the scalaranic skeleton and further transformations

“…Recently (Soetjipto et al, 2000;Furuichi et al, 2001), a cascade method of synthesis of a norscalaranic b-ketoester 27 has been elaborated, starting from b-cyclogeraniol 86 in 15 steps (Scheme 12). Racemic tetracyclic compound 27 was obtained in an overall yield of 15%.…”