Ε. C 30 Sterols
81
3. 9,1 1-SECOGORGOST-5-EN-3,1 1-DIOL-9-ONE
Perhaps the most unusual C 30 marine sterol is the gorgosterol derivative with
a cleaved ring C that was isolated by Weinheimer et al, (1970) from the
gorgonian Pseudopterogorgia
americana along with gorgosterol and was
assigned structure 38 on the basis of chemical and spectral evidence. Interestingly, the 5cc6ci-epoxide was also isolated from the gorgonian. Full experimental details of these fascinating compounds are still lacking, but structure
38 was confirmed by X-ray diffraction of the 3ß-/?-iodobenzoate (Enwall et al,
1972).
38
4. 23-DEMETHYLGORGOSTEROL
The final compound in the group, 23-demethylgorgosterol (39) is, as had
been pointed out, a C 29 sterol, but generically it belongs with this group of
C 30 compounds. As mentioned in Section D, 11 it was isolated by Schmitz
and Pattabhiraman (1970) from two gorgonians. Its structure was determined
by spectral methods and confirmed by an X-ray diffraction study of the 3-iodobenzoate (Hsu and vander Helm, 1971 ; Enwall et al, 1972).
39
5. 29-METHYLISOFUCOSTEROL
A C 30 sterol without a cyclopropane in the side chain, but with a propylidene group at C-24 was recently reported by Idler and co-workers (1971,
1972). These workers isolated this sterol (40) from the scallop Placopecten
81
3. 9,1 1-SECOGORGOST-5-EN-3,1 1-DIOL-9-ONE
Perhaps the most unusual C 30 marine sterol is the gorgosterol derivative with
a cleaved ring C that was isolated by Weinheimer et al, (1970) from the
gorgonian Pseudopterogorgia
americana along with gorgosterol and was
assigned structure 38 on the basis of chemical and spectral evidence. Interestingly, the 5cc6ci-epoxide was also isolated from the gorgonian. Full experimental details of these fascinating compounds are still lacking, but structure
38 was confirmed by X-ray diffraction of the 3ß-/?-iodobenzoate (Enwall et al,
1972).
38
4. 23-DEMETHYLGORGOSTEROL
The final compound in the group, 23-demethylgorgosterol (39) is, as had
been pointed out, a C 29 sterol, but generically it belongs with this group of
C 30 compounds. As mentioned in Section D, 11 it was isolated by Schmitz
and Pattabhiraman (1970) from two gorgonians. Its structure was determined
by spectral methods and confirmed by an X-ray diffraction study of the 3-iodobenzoate (Hsu and vander Helm, 1971 ; Enwall et al, 1972).
39
5. 29-METHYLISOFUCOSTEROL
A C 30 sterol without a cyclopropane in the side chain, but with a propylidene group at C-24 was recently reported by Idler and co-workers (1971,
1972). These workers isolated this sterol (40) from the scallop Placopecten