@article {47633,
	title = {Bismuth(iii)-catalyzed bis-cyclization of propargylic diol-esters: a unified approach for the synthesis of [5,5]- and [6,5]-oxaspirolactones},
	journal = {Organic \& Biomolecular Chemistry},
	volume = {19},
	year = {2021},
	month = {AUG },
	pages = {6618-6622},
	type = {Article},
	abstract = {Herein we disclose an unprecedented intramolecular cascade strategy for the construction of alpha,beta-unsaturated [5,5]- and [6,5]-oxaspirolactones that capitalizes on the pi-electrophilic Lewis acid-catalyzed 5-exo-dig or 6-exo-dig mode of cyclization of propargylic diol esters, followed by dehydration and spirolactonization steps. Moreover, semi-protected substrates also delivered the respective oxaspirolactones with the same ease and in appreciable yields under optimal reaction conditions.},
	issn = {1477-0520},
	doi = {10.1039/d1ob00974e},
	author = {Kambale, Digambar A. and Borade, Balasaheb R. and Kontham, Ravindar}
}
@article {48937,
	title = {Bi(OTf)3-promoted cascade annulation of hydroxy-pyranones and unsaturated γ-ketoesters for the construction of polycyclic bridged pyrano-furopyranones},
	journal = {Organic and biomolecular chemistry},
	volume = {22},
	year = {2024},
	month = {JAN },
	pages = {496-500},
	type = {Article},
	abstract = {<p>An efficient protocol for constructing complex three dimensional polycyclic bridged chromano-furopyranones and pyrano-furopyranones (closely related to bioactive natural products) via bismuth(III)-catalyzed cascade annulation of hydroxy-pyranones and unsaturated gamma-ketoesters is presented. This process involves intermolecular Michael addition, intramolecular hemiketalization, lactonization, formation of one C-C bond and two C-O bonds, rings, and contiguous stereocenters.</p>
},
	keywords = {1 3-Dicarbonyl Compounds, alkynols, Coumarins, Fungus},
	issn = {1477-0520},
	doi = {10.1039/d3ob01862h},
	author = {Rathod, Akshay B. and Borade, Balasaheb R. and Sambherao, Pooja I. and Kontham, Ravindar}
}
