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A series of new 3,4-ethylenedioxy-2-thenyl (EDOTn) derived alcohols have been synthesized and evaluated as super acid labile carboxylic acid protecting groups. All the derivatives are labile to very low concentrations of TFA (0.01–0.5%).

p-Nitrobenzyloxycarbonyl (pNZ) is used for the permanent protection of ornithine in the synthesis of derivatives of the anti-tumor cyclodepsipeptide Kahalalide F that contain acid labile residues.

Semipermanent side-chain protection of Orn and Lys with p-nitrobenzyloxycarbonyl (pNZ) for Fmoc/tBu chemistry does not result in the unwanted removal of α-Fmoc that occurs when groups such as Alloc are used for the same application. Furthermore, pNZ can be used in conjuction with p-nitrobenzyl ester (pNB) to prepare cyclic peptides.

Efficient modular synthetic routes to open chain marine alkaloids such as lamellarins have been developed. 5,6-Dihydropyrrolo[2,1-b]isoquinoline scaffolds were prepared, and protocols enabling regioselective bromination followed by Suzuki cross-coupling were established for the introduction of aryl groups onto the 2- and 3-positions.

An effective solid-phase preparation of the pharmaceutically interesting 4 H -2-(3-hydroxy-4-methoxyphenyl)-naphtho[1,2- b ]pyran-1-one system from an anchored bisarylacetylene is described.

(S)-2-(4-Bromo-2,4′-bithiazole)-1-(tert-butoxycarbonyl)pyrrolidine ((S)-1) was obtained as a single enantiomer and in high yield by means of a two-step modified Hantzsch thiazole synthesis reaction when bromoketone 3 and thioamide (S)-4 were used. Further conversion of (S)-1 into trimethyltin derivative (S)-2 broadens the scope for further cross-coupling reactions.

The use of methyl 2-(1,3-dithian-2-yl)benzoate as a member of a new group of bidentate synthons in an improved annelation method, yielding polycyclic systems with three differentiated carbonyl groups, is described.

Treatment of dithioacetals 1a–c, 3, and 4 with DMTSF accomplishes cyclization upon the indole 3-position to give the Strychnos -type pentacles 2a–c, 10, and 11 , respectively.

6,7-Dimethoxy-4-methylquinoline has been converted in nine steps into the sulfur-containing pyrrolo[4,3,2- de ]quinoline marine alkaloid isobatzelline B. This constitutes the first total synthesis of an alkaloid of the group which contains a methylthio substituent.

A short, new route to the title tetracyclic substructure of Strychnos alkaloids, consisting in the nucleophilic attack of an ester α-anion to a pyridinium salt, acid-induced cyclization of the resultant 1,4-dihydropyridine, and stereospecific elaboration of the ethylidene substituent, is reported.