128
Fig. 52 Guaiane-, pseudoguiane-, and aromadendrane-type sesquiterpenoids
(65), 73, and 74, and two noreremophilanes, ligudentatol (118) and rumicifoline A
(129), were isolated. Alcohols 57 and 58 proved to be epimeric compounds at C-1.
Bisabolanes with various esters at different positions, inclusive of rumicifoline P
(655), 659, songaricalarin F (660), rumicifoline Q (662), rumicifoline N (665), 667,
rumicifoline M (668), rumicifoline O (674), fararone A (706), rumicifoline R (714),
5α-angeloyloxyrumicifoline R (715), 716, tussfararin F (717), and altaicalarin B
(718), were purified. This sample also produced the polyoxygenated oplopanes,
rumicifoline D (739), rumicifoline E (740), rumicifoline F (741), (4E)-rumicifoline
G (742), (4Z)-rumicifoline G (743), (4E)-rumicifoline H (744), (4Z)-rumicifoline H
(745), rumicifoline I (746), 747, rumicifoline B (755), and rumicifoline C (756).
The structure of rumicifoline B (755) was confirmed by X-ray crystallographic
analysis. The absolute configurations at C-4 and C-11 were determined to be (4R)
and (11S). A comment should be made on how to draw properly the structures of
bisabolanes. Since the bisabolane skeleton has a plane of symmetry, the substituent
at C-6 of the cyclohexane ring is recommended to be oriented as β [296].
M. Tori and C. Kuroda
Fig. 52 Guaiane-, pseudoguiane-, and aromadendrane-type sesquiterpenoids
(65), 73, and 74, and two noreremophilanes, ligudentatol (118) and rumicifoline A
(129), were isolated. Alcohols 57 and 58 proved to be epimeric compounds at C-1.
Bisabolanes with various esters at different positions, inclusive of rumicifoline P
(655), 659, songaricalarin F (660), rumicifoline Q (662), rumicifoline N (665), 667,
rumicifoline M (668), rumicifoline O (674), fararone A (706), rumicifoline R (714),
5α-angeloyloxyrumicifoline R (715), 716, tussfararin F (717), and altaicalarin B
(718), were purified. This sample also produced the polyoxygenated oplopanes,
rumicifoline D (739), rumicifoline E (740), rumicifoline F (741), (4E)-rumicifoline
G (742), (4Z)-rumicifoline G (743), (4E)-rumicifoline H (744), (4Z)-rumicifoline H
(745), rumicifoline I (746), 747, rumicifoline B (755), and rumicifoline C (756).
The structure of rumicifoline B (755) was confirmed by X-ray crystallographic
analysis. The absolute configurations at C-4 and C-11 were determined to be (4R)
and (11S). A comment should be made on how to draw properly the structures of
bisabolanes. Since the bisabolane skeleton has a plane of symmetry, the substituent
at C-6 of the cyclohexane ring is recommended to be oriented as β [296].
M. Tori and C. Kuroda