CYCLOPETIDE ALKALOIDS. SYNTHETIC, SPECTROSCOPIC AND CONFORMATIONAL STUDIES OF PHENCYCLOPEPTINE MODEL COMPOUNDS
Peptide cyclization via the p-nitrophenyl ester of 4-methyl-3-[4'-{beta}-N-(N'-tert-butyloxycarbonyl-L~prolyl)-aminoethyl]phenoxy-pentanoic acid (9) has afforded a single cyclopeptide diastereomer,9R-isopropyl-5S,6-trimethylene-8-dearnino-1,2-dihydro-p-phencyclopeptine (4), in 36% yield. From the comparative analysis of the UV, IR, CD, and {sup 1}H NMR spectra of 4 and cyclopeptide 5S,6-trimethylene 8-deamino-1,2-dihydro-p-phencyclopeptine (3d), of known geometry, the conformational identities of the 14-membered ring systems were ascertained. From these data the assignment of R stereochemistry at C9 for cyclopeptide 4 was deduced. Since the stereochemistry at C9 in the naturally occurring phencyclopeptines is the same, these results suggest a feasible route to the stereoselective total synthesis of the phencyclopeptines.
- Research Organization:
- Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
- Sponsoring Organization:
- Chemical Sciences Division
- DOE Contract Number:
- AC02-05CH11231
- OSTI ID:
- 1070086
- Report Number(s):
- LBL-11024
- Journal Information:
- Journal of Organic Chemistry, Journal Name: Journal of Organic Chemistry Journal Issue: 24 Vol. 45; ISSN 0022-3263
- Country of Publication:
- United States
- Language:
- English
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