Dysidin

Marine organisms have provided very complex molecules possessing a pyr-rolidinone ring as part of a urea function dysidin (105) (140), malyngamide A (106) (141) and pukeleimides A, B, C, D, E, F, and G (107-113) (142, 143). 

A reaction by Clough et al. comes close to the direct synthesis shown in Scheme 1 (89TL7469). Here amides (62) react in a radical mechanism to 4-methylene compounds (63) that with 03/PPh3 are converted to tetramic acids (64). (See Fig. 29.) Several authors, however, prepared esters of 4-amino-3-oxo-butanoic acid, which served as precursors for intramolecular cyclization to tetramic acids (82JHC883). Koehler and Gerlach in an initial stage of a synthesis of dysidine, contained in marine sponge... 

Mycosporine-2 is a fungal metabolite of Botrytis cinerea, and is formulated as the pyrrolidone (5) on mass and 13C and H n.m.r. spectral evidence.9 The marine sponge Dysidea herbacea secretes a chlorine-containing pyrrolinone dysidine, formulated as (6) as a consequence of degradative and spectroscopic studies. Its relative and absolute configurations were settled by X-ray diffraction methods.10 On exposure to strong base the compound is degraded to the pyrrolinone (7), which was synthesized from L-valine methyl ester, and the acid (8), identified by its mass and n.m.r. spectral behaviour.10... 

Figure 7 Structures of compounds 27 and 28 (the microcolins), 29 (malyngamide A), 30 (majusculamide D), 31 (dysidin) and 32 (dolastatin 18).

Several thiazole-containing linear peptides such as dysidenin, isodysidenin, and dysidin have been isolated from marine invertebrates and their absolute configurations have been established (80T2133, 93JOC6336,95TLii85>. However, the total synthesis of any of these compounds has not been reported. 

Williard, P.G., and S.E. de Laszlo Total Synthesis of ( )-Dysidin, a Marine Metabolite Containing an N-Acyl-O-methyltetramic Acid. J. Org. Chem. 49, 3489 (1984). 

CHLOROLEUCINE PEPTIDES, DYSIDIN, NEODYSIDENIN, AND RELATED COMPOUNDS... 

Kohler H, Gerlach H. Synthese des Dysidins. Helv. Chim. Acta. 1984 67(7) 1783-1792. 

WiUiard PG, De Laszlo SE. Total synthesis of ( )-dysidin, a marine metabolite containing an V-acyl-O-methyltetramic acid. J. Org. Chem. 1984 49(19) 3489-3493. 

Ilardi EA, Zakarian A. Efficient total synthesis of dysidenin, dysidin, and barbamide. Chem. Asian J. 2011 6(9) 2260-2263. 

Beware to a possible confusion with the merosesquiterpene dysidine (see Rg. 104B) Dysideamine is structurally related to bolinaquinone (see Rg. 104B)... 

Hofheinz, W. and Oberhansli, W.E. (1977) Dysidin, ein neuartiger, chlorhaltiger naturstoff aus dem schwamm Dysidea herbacea. Helv. Chim. Acta, 60, 660-669. 

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