Philip Magnus

Origins of 1,2- and 1,3-stereoselectivity in dicobaltoctacarbonyl alkene-alkyne cyclizations for the synthesis of substituted bicyclo[3.3.0]octenones

Abstract A working mechanistic hypothesis is proposed which rationalizes the stereochemical outcome of the synthesis of substituted bicyclo[3.3.O]octenones, using dicobaltoctacarbonyl mediated alkene-alkyne cyclizations.

Dicobaltoctacarbonyl ‐ Alkyne Complexes as Intermediates in the Synthesis of Bicyclo[3.3.0]octenones for the Synthesis of Coriolin and Hirsutic Acid.

Abstract Treatment of the readily prepared enzymes 12, 21 and 45 with Co2(CO) at ca 110° results in high yields (80%) of substituted bicyclo[3.3.0]octenones, that are suitable for straightforward elaboration into coriolin and hirsutic acid precursors. A mechanistic hypothesis to explain the observed stereospecificity is presented.

Studies on the antitumor agent CC-1065 : 1-Phenylsulfonyl-1,3-butadiene. An electrophilic equivalent to 1,3-butadiene for the synthesis of 3,31-bipyrroles.

Abstract Sequential conjugate additions of methyl TOSMIC anion and TOSMIC anion to 1-phenylsulfonyl-1,3-butadiene provides a direct route to 3,3 1 -bipyrroles, and illustrates that 1-phenylsulfonyl-1, 3-butadiene can function as an electrophilic 1,3-butadiene equivalent.

Indole-2,3-quinodimethanes : Synthesis of selectively protected derivatives of the fused dimeric indole alkaloid staurosporinone

Abstract The imine 1 was converted via an indole-2,3-quinodimethane cyclization to the hexahydroindolocarbazole 7, which was further converted to the N-carbomethoxy derivative of staurosporinone 2.

Studies on the hydrocarboxylation of N-acetylimines, enamines and allylamines.

Abstract Treatment of an amide with an aldehyde in the presence of CO2(CO)8/CO/H2 results in N -acyl- α -amino acids. The scope and limitations of this reaction are explored.

Indole-2, 3-quinodimethanes: Synthesis of indolocarbazoles for the synthesis of the fused dimeric indole alkaloid staurosporinone

Abstract N-[(4-Methoxyphenyl)sulfonyl]-3-ethyl-2-formylindole, made by direct electrophilic formylation of N-[(4-methoxylphenyl)sulfonyl]-3-ethylindole using α, α-dichloromethylmethylether/TiCl 4 , was converted into the imine 23 by treatment with 2-aminostyrene The imine 23 , on treatment with methylchloroformate gave the hexahydroindolocarbazole 24 , which was dehydrogenated (DDQ) to give the completely aromatic system 25 Other examples of this type of methodology for the synthesis of both indolocarbazoles and pyrrolocarbazoles are described.

Studies on the antitumor agent CC-1065

Abstract The 3,31-bipyrrole 4 is readily converted into o -quinone 5 , which was regiospecifically elaborated into the CC-1065 B/C-model component 15 by sequential reduction, alkylation and reduction reactions.

Synthetic studies on the esperamicin/calicheamicin antitumor antibiotics. Conjugate addition of thiol to initiate 1,4-diyl formation

Abstract Intermolecular thiol addition to the bicyclo[7.3.1]diynenone 9 allows access to the C-1 sp 3 hybridized derivative 9a , which in turn undergoes cycloaromatization to give the bicyclo[3.3.1]system 10 .

Methods for indole alkaloid synthesis:Reactions of n-arylsulfonylenamines with electrophiles. An expeditious synthesis of (±)-eburnamonine.

Abstract Treatment of 4 with MCPBA gave 9 . The pentacyclic amide 3 on exposure to cyanogen chloride gave the cis-chloro-hydrin 20 , and the geminal dichloride 21 . When 21 was treated with HCl/MeOH it rapidly rearranged to eburnamonine lactam 22 .

Methods for indole alkaloid synthesis. A highly convergent strategy for the synthesis of a 3-methyl-6,7-dehydroaspidospermidine system.

Abstract The N 1 -CO 2 ME derivative of 2-ethyl-3-formylindole has been converted into the highly functionalized aspidospermidine - type alkaloid 12 in four steps.