Synthesis of phalluside-1 and Sch II using 1,2-metallate rearrangements.

(4E,8E,10E)-9-Methyl-4,8,10-sphingatrienine, a core component of marine sphingolipids, was synthesised for the first time using a copper(I)-mediated 1,2-metallate rearrangement of a lithiated glycal as a key step. It was converted to phalluside-1, a cerebroside isolated from the ascidian Phallusia fumigate. By an analogous route, (4E,8E)-9-methyl-4,8-sphingadiene was synthesised and converted to Sch II, a cerebroside that induces fruiting body formation in the basidiomycete Schizophyllum commune.

A synthesis of an ionomycin calcium complex.

Caught in the middle: The ionomycin calcium complex (see structure; O red, Ca green) was the target of an approach featuring the efficient asymmetric synthesis of an allene by a copper(I)-mediated anti-selective S(N)2' reaction, a highly stereoselective gold(III)-catalyzed cycloisomerization of an alpha-hydroxyallene, and a Rh-catalyzed rearrangement of an alpha-diazo-beta-hydroxyketone.

Synthesis of the C1-C16 fragment of ionomycin using a neutral (eta3-allyl)iron complex.

Key steps in the synthesis of the C1-C16 polyketide fragment of ionomycin were the nucleophilic addition of an organocuprate to a neutral (eta3-allyl)iron complex and the construction of a beta-diketone moiety by the Rh-catalysed rearrangement of an alpha-diazo-beta-hydroxyketone.

Synthesis of (S)-(-)-N-acetylcolchinol using intramolecular biaryl oxidative coupling.

An asymmetric synthesis of the tubulin polymerisation inhibitor (S)-(-)-N-acetylcolchinol is reported based on an intramolecular biaryl oxidative coupling of a 1,3-diarylpropyl acetamide intermediate using phenyliodonium bis(trifluoroacetate) as the final step. Three syntheses of the penultimate 1,3-diarylpropyl acetamide intermediate (S)-(-)-N-[1-[3-(tert-butyldimethylsilyloxy)phenyl)]-3-(3,4,5-trimethoxyphenyl)propyl] acetamide are described which differ in the means by which the stereogenic centre was introduced.

The nucleophilic addition of alpha-metallated 1,3-dioxanes to planar chiral cationic eta3-allylmolybdenum complexes. Synthesis of (2E,5S,6R,7E)-6-methyl-8-phenylocta-2,7-dienoic acid methyl ester, a key component of the Cryptophycins.

Two adjacent stereogenic centres and a pendant alkene were constructed via nucleophilic addition of a 1,3-dioxan-4-ylcopper(I) reagent to a cationic eta3-allylmolybdenum complex as part of a synthesis of (2E,5S,6R,7E)-6-methyl-8-phenylocta-2,7-dienoic acid, a key component of the Cryptophycins. Oxidative addition of Mo(CO)(4)(THF)(2) to allyl benzoates provides an efficient synthesis of eta3-allylmolybdenum(dicarbonyl) complexes.

Synthesis of (+)-manoalide via a copper(I)-mediated 1,2-metalate rearrangement.

An enantiospecific synthesis of the phospholipase A(2) inhibitor (+)-(4R)-manoalide is reported in which all 25 carbons of the sesterterpenoid skeleton are constructed from 3-furaldehyde, trimethylalane, oxirane, CO, beta-ionone, and propargyl bromide. The overall yield for the longest linear sequence (12 steps) is 12%. Key steps include (a) a zirconium-catalyzed carboalumination reaction to construct the C10-C11 trisubstituted alkene, (b) a Cu(I)-mediated 1,2-metalate rearrangement to construct the C6-C7 trisubstituted alkene, (c) a Sharpless kinetic resolution to secure the (4R)-stereochemistry, (d) generation of a 5-stannyl-2,3-dihydrofuran by Mo-catalyzed cycloisomerization of a homopropargylic alcohol, and (e) construction of the hydroxyfuranone ring by photooxidation of a silylfuran.

Synthesis of D-erythro-sphingosine and D-erythro-ceramide.

A 1,2-metallate rearrangment of a higher order cuprate derived from an alpha-lithiated xylal derivative and tridecyllithium is the key step in a synthesis of D-erythro-sphingosine and ceramide. A convenient method for preparing alpha-lithiated glycals from alpha-phenylsulfinyl glycals is also described.

Solid-phase synthesis of c(RGDfK) derivatives: on-resin cyclisation and lysine functionalisation.

The cyclic pentapeptide c(RGDfK), a selective ligand for the alpha(v)beta3 integrin, was synthesised on solid phase. All synthetic operations including the cyclisation step and the appendage of the Bolton-Hunter reagent was conducted on-resin.