@article {44631,
	title = {Four-step total synthesis of (+)-yaoshanenolides A and B},
	journal = {ACS Omega},
	volume = {3},
	year = {2018},
	month = {JUN},
	pages = {7036-7045},
	abstract = {<p>A highly concise bioinspired four-step total synthesis of yaoshanenolides A and B possessing tricyclic spirolactone with an unusual 5{\textquoteright}H-spiro-[bicyclo[2.2.2]-oct[2] ene-7,2{\textquoteright}-furan]-5{\textquoteright}-one scaffold is reported. This synthesis features high-yielding aldol-type addition of gamma-butyrolactone on to the aldehyde, exocyclic olefination of lactone derivative using Eschenmoser{\textquoteright}s salt, and highly facial-and endo-selective [4 + 2]-cycloaddition of fully functionalized 5-methylene-2(5H)-furanone with natural R-(-)-alpha-phellandrene. The approach allows access to yaoshanenolides A and B in four linear steps in 11 and 13\% overall yield.</p>},
	issn = {2470-1343},
	doi = {10.1021/acsomega.8b00701},
	author = {Thorat, Sagar S. and Palange, Megha N. and Kontham, Ravindar}
}
@article {46081,
	title = {TiCl4-n-Bu3N-mediated cascade annulation of ketones with alpha-ketoesters: a facile synthesis of highly substituted fused gamma-alkylidene-butenolides},
	journal = {Organic \& Biomolecular Chemistry},
	volume = {17},
	year = {2019},
	month = {JUN},
	pages = {5749-5759},
	type = {Article},
	abstract = {<p>A facile protocol for the synthesis of highly substituted fused gamma-alkylidene butenolides using direct annulation of ketones with alpha-ketoesters, which proceeds through TiCl4-n-Bu3N mediated aldol addition followed by an intramolecular enol-lactonization/cyclization cascade, is reported. Diverse 6-5, 7-5 and 8-5 fused bicyclic gamma-ylidene butenolides and highly substituted monocyclic analogs related to biologically relevant natural products were prepared from readily accessible ketone and alpha-ketoester building blocks. The highly step-economic cascade nature, good substrate scope, easy access to complex products with good to excellent yields, gram-scalability, demonstration of synthetic utility, and unambiguous structural confirmation through X-ray crystallography analyses and analogy are the salient features of this work.</p>
},
	issn = {1477-0520},
	doi = {10.1039/c9ob00649d},
	author = {Palange, Megha N. and Gonnade, Rajesh G. and Kontham, Ravindar}
}
