@article {818,
	title = {The crystal structure of a simple enol formed in a single-crystal-to-single-crystal enolene rearrangement},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {82},
	number = {2},
	year = {2004},
	note = {ISI Document Delivery No.: 802BHTimes Cited: 1Cited Reference Count: 15},
	month = {Feb},
	pages = {301-305},
	type = {Article},
	abstract = {When crystals of 9-tricyclo[4.4.1.0]undecalyl-4-(carbomethoxy)phenyl ketone (1) were allowed to stand in the dark for extended periods of time at room temperature, the compound underwent a thermal reaction - the enolene rearrangement - to afford enol 2. The crystals remained transparent and appeared unchanged in shape as the reaction proceeded. X-ray diffraction data were collected on single crystals containing 17\%, 25\%, 66\%, and 100\% of the enol. The crystal structure of a simple enol was obtained via this novel single-crystal-to-single-crystal enolene rearrangement.},
	keywords = {enol, enolene, HYDROGEN-ATOM ABSTRACTION, PHOTODIMERIZATION, REARRANGEMENT, single crystal, STATE, thermal},
	isbn = {0008-4042},
	url = {<Go to ISI>://000220138500026},
	author = {Chong, K. C. W. and Patrick, B. O. and Scheffer, J. R.}
}
@article {3754,
	title = {Stereoselective synthesis of new chlorophyll A related antioxidants isolated from marine organisms},
	journal = {Journal of Organic Chemistry},
	volume = {61},
	number = {7},
	year = {1996},
	note = {ISI Document Delivery No.: UD653Times Cited: 39Cited Reference Count: 37},
	month = {Apr},
	pages = {2501-2510},
	type = {Article},
	abstract = {A new class of natural antioxidants, chlorophyll a related chlorins 3, 4(S), 4(R), 5(R), 6, 7, 8, and 9, have been synthesized from a chlorophyll a degradation product, pheophorbide a methyl ester (1). Claisen-type intramolecular condensation of pyropheophorbide a methyl ester (2) afforded the common intermediate enol 3. Chlorin 1 and enol 3 have a propensity to undergo exocyclic ring opening by ionic bases. The organic base DBU was found to be an efficient reagent for promoting the asymmetric hydroxylation of these chlorins, using N-sulfonyloxaziridines, without cleavage of the exocyclic rings. Model studies for hydroxylactonization have shown that periodate oxidation of hydroxy ketone 10 stereoselectively and predominantly forms hydroxy lactone 17(S). Periodate oxidation of alpha-hydroxy 1,3-diketone 4(R) and/or 4(S) to furnish hydroxy lactone 5(R) and diketone 7 was found out to be regioselective, and the site of reaction depends on the appropriate choice of reaction media. H-1 NMR spectra have provided information on the absolute configuration of diastereomers at the C-13(2) or C-15(1) position.},
	keywords = {2-SULFONYLOXAZIRIDINES, CHEMISTRY, COMPOUND, DERIVATIVES, enol, HYDROXYLATION, ORIGINS, RCI, RUDITAPES-PHILIPPINARUM},
	isbn = {0022-3263},
	url = {<Go to ISI>://A1996UD65300039},
	author = {Ma, L. F. and Dolphin, D.}
}
@article {3753,
	title = {Synthesis and spectral studies of natural chlorins having antioxidative activity},
	journal = {Pure and Applied Chemistry},
	volume = {68},
	number = {3},
	year = {1996},
	note = {ISI Document Delivery No.: UM994Times Cited: 3Cited Reference Count: 1510th International Conference on Organic SynthesisDEC 11-16, 1994BANGALORE, INDIAInt Union Pure \& Appl Chem, Organ Chem Div, Indian Natl Sci Acad, Natl Organ Symp Trust, India, Indian Inst Sci, Jawaharlal Nehru Ctr Adv Sci Res},
	month = {Mar},
	pages = {765-769},
	type = {Proceedings Paper},
	abstract = {Starting from pheophorbide a methyl ester (1), a degradation product of chlorophyll a, novel natural antioxidants of chlorophyll a related chlorins 3, 5(S), 5(R), 8(R), 9-13 have been synthesized in high yields. Key steps involve formation of 5(R) and 5(8) via a DBU-promoted asymmetric hydroxylation of 3, and regioselective periodate oxidations of 5 to 8(R) and 9.},
	keywords = {COMPOUND, enol, RUDITAPES-PHILIPPINARUM},
	isbn = {0033-4545},
	url = {<Go to ISI>://A1996UM99400059},
	author = {Ma, L. F. and Dolphin, D.}
}
@article {3440,
	title = {ASYMMETRIC HYDROXYLATION OF CHLOROPHYLL DERIVATIVES - A FACILE ENTRY TO BOTH DIASTEREOMERS OF CHLOROPHYLLONE A},
	journal = {Tetrahedron-Asymmetry},
	volume = {6},
	number = {2},
	year = {1995},
	note = {ISI Document Delivery No.: QK514Times Cited: 12Cited Reference Count: 8},
	month = {Feb},
	pages = {313-316},
	type = {Note},
	abstract = {High stereoselectivity is observed for the asymmetric oxidation of chlorophyll enolates derived from 13(2),17(3)-pheophorbide a enol (3), pheophorbide a methyl ester (8) and pheophytin a (9) with DBU and N-sulfonyl oxaziridines (4), (5) and (6).},
	keywords = {enol},
	isbn = {0957-4166},
	url = {<Go to ISI>://A1995QK51400001},
	author = {Ma, L. F. and Dolphin, D.}
}
