The Role of Total Synthesis in Structure …
29
Table 1
(continued)
Entry
Stagonolide
Status of structure elucidation after
total synthesis
Confirmed or revised structure
based on synthesis
Source of chirality in total syntheses Ref.
23
Lipase-cat. kinetic resolution
[113]
24
d- and
l-Proline cat.
α-hydroxylation [114]
25
d- and
l-Proline cat.
α-hydroxylation [115]
26
(S)-5-Hexene-2-ol; asymmetric
dihydroxylation (formal synthesis)
[116]
27
Stagonolide F (89)
Structure assigned for stagonolide F
has been questioned; renaming to
(–)-5-epi-aspinolide A was proposed
No revised structure proposed so
far
Co-salen cat. epoxide hydrolytic
resolution and Sharpless epoxidation
(synthesis of published structure and
confirmation proposed)
[117]
28
Asymmetric dihydroxylation;
R-propylene
oxide (synthesis of
published structure and confirmation
proposed)
[118]
29
Asymmetric organocat.
α-hydroxylation and epoxidation
(synthesis of published structure and
confirmation proposed)
[119]
30
(R)-Propylene oxide; separation of
diastereomers after
Nozaki-Hiyama-Kishi-cyclization
(synthesis of structure 89,
but
significant discrepancies with data
published for natural and synthetic
stagonolide F reported; re-naming of
89
to (–)-5-epi-aspinolide A
proposed)
[23]
(continued)