The syntheses, characterizations and transformations of three tetraphenylporphyrins derived from methoxymethylated benzaldehyde 3 are described. Benzaldehyde 3 reacted with pyrrole under Lewis acid catalysis to give dipyrromethane 4 which was used as precursor in porphyrin syntheses. Porphyrins 6, αα-7 and αβ-7 were obtained using conditions for sterically encumbered benzaldehydes, with αα-7 and αβ-7 being atropisomers. The methoxymethyl groups of 6, αα-7 and αβ-7 were transformed into bromomethyl substituents (porphyrins 8, αα-9 and αβ-9) which were easily modified by nucleophilic reaction with the azide anion. Porphyrin azide 10 was subjected to a Staudinger phosphazene formation with triphenylphosphine. Subsequent reaction of the porphyrin phosphazene 12 with carboxylic acids gave acetamide 13, benzamide 14, and ferrocene carboxamide 15, respectively. Kornblum oxidation of monobromomethyl porphyrin 8 gave the formyl derivative 16.

The stereoselective synthesis of the fully functionalized northern hemisphere of the marine natural product amphidinolide H2 is described. A vinylogous Mukaiyama aldol reaction and enzymatic desymmetrization of a meso compound are the key steps in the fragment synthesis. A stereoselective acetate aldol coupling and a 1,3-anti-reduction of the resulting b-hydroxy ketone complete the synthesis of the C14-C26 fragment.

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