@article { ISI:000287163000011,
	title = {Construction of the 5,10b-phenanthridine skeleton using [3+2]-cycloaddition of a non-stabilized azomethine ylide: total synthesis of (+/-)-maritidine and (+/-)-crinine alkaloids},
	journal = {European Journal of Organic Chemistry},
	number = {4},
	year = {2011},
	month = {FEB},
	pages = {740-750},
	publisher = {WILEY-V C H VERLAG GMBH},
	address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY},
	abstract = {<p>Vicinal quaternary and tertiary stereocenters of the 5,10b-phenanthridine skeleton 1 are constructed simultaneously in one step by the [3+2]-cycloaddition of non-stabilized azomethine ylide 9, generated by sequential double desilylation of 10 utilizing silver(I) fluoride as a one-electron oxidant. The regioas well as stereochemical origin of this cycloaddition reaction is explained through a favorable transition state 9{\textquoteright}{\textquoteright}. The strategy is successfully applied for the total synthesis of the biologically active alkaloids (+/-)-maritidine (1a), (+/-)-crinine (1b), and their analogues (1d, 1e, and 1f).</p>},
	keywords = {alkaloids, Azomethine ylides, Cycloaddition, Natural products, Ylides},
	issn = {1434-193X},
	doi = {10.1002/ejoc.201001263},
	author = {Pandey, Ganesh and Gupta, Nishant R. and Gadre, Smita R.}
}
@article { ISI:000294656400011,
	title = {One-step stereospecific strategy for the construction of the core structure of the 5,11-methanomorphanthridine alkaloids in racemic as well as in optically pure form: synthesis of (+/-)-pancracine and (+/-)-brunsvigine},
	journal = {European Journal of Organic Chemistry},
	number = {24},
	year = {2011},
	month = {AUG},
	pages = {4571-4587},
	publisher = {WILEY-V C H VERLAG GMBH},
	address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY},
	abstract = {<p>The unique core structure of the complex pentacyclic 5,11-methanomorphanthridine has been constructed stereospecifically in one step by an intramolecular [3+2] cycloaddition of a non-stabilized azomethine ylide (AMY), generated by the sequential double desilylation of 14 using (AgF)-F-I as a one-electron oxidant. The formation of the single diastereomer in the key step is explained by the preferred transition state produced by endo attack of the AMY on the {\textquoteleft}{\textquoteleft}Re{\textquoteright}{\textquoteright} face of the dipolarophile. An asymmetric version of the cycloaddition using a chiral dipolarophile was applied to construct the core structure 68 with 63 \% ee. This strategy was successfully applied to the formal synthesis of (+/-)-pancracine and the total synthesis of (+/-)-brunsvigine. An unprecedented and interesting skeletal rearrangement product 49 was observed during the attempted assembly of the E ring from 46 through Horner-Wadsworth-Emmons reactions. Mechanisms involving azetidinium salt formation or the Grob-type fragmentation are advanced to explain the observed rearrangement.</p>},
	keywords = {alkaloids, Azomethine ylides, Cycloaddition, Ring-closing metathesis, synthesis design},
	issn = {1434-193X},
	doi = {10.1002/ejoc.201100601},
	author = {Pandey, Ganesh and Kumar, Ravindra and Banerjee, Prabal and Puranik, Vedavati G.}
}
