Synthesis of Chromen[4,3-b]pyrrolidines by Intramolecular 1,3-Dipolar Cycloadditions of Azomethine Ylides: An Experimental and Computational Assessment of the Origin of Stereocontrol

Azomethine ylides, generated from imine-derived O-cinnamyl or O-crotonyl salicylaldeyde and α-amino acids, undergo intramolecular 1,3-dipolar cycloaddition, leading to chromene[4,3-b]pyrrolidines. Two reaction conditions are used: (a) microwave-assisted heating (200 W, 185 °C) of a neat mixture of reagents, and (b) conventional heating (170 °C) in PEG-400 as solvent. In both cases, a mixture of two epimers at the α-position of the nitrogen atom in the pyrrolidine nucleus was formed through the less energetic endo-approach (B/C ring fusion). In many cases, the formation of the stereoisomer bearing a trans-arrangement into the B/C ring fusion was observed in high proportions. Comprehensive computational and kinetic simulation studies are detailed. An analysis of the stability of transient 1,3-dipoles, followed by an assessment of the intramolecular pathways and kinetics are also reported.

A summary of remarks made by William C. Lane, Librarian of Harvard University, published in the Proceedings of the Massachusetts Historical Society, December 1909

Lane addressed the Massachusetts Historical Society about the recent discovery of foundations walls, likely from Goffe College, made during the Boston Elevated Railway's excavations in Harvard Square for the subway on Massachusetts Avenue.

Handbook of British fungi, with full descriptions of all the species, and illustrations of the genera. By M. C. Cooke, M.A.

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Handbook of British fungi, with full descriptions of all the species, and illustrations of the genera. By M. C. Cooke, M.A.

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Unique construction of an exhibit of Pliocene edentates / by Phil C. Orr --.

no.5(1938)

Studies of American plants. by Paul C. Standley.

v.22:no.3(1940)

An account of my quarter bills, charges &c from July 11th 1743 to July 13th 1748 at Harvard College

Handwritten account book kept while Storer was a student at Harvard College. The well-organized volume is arranged by expense type and then date and was updated periodically, usually quarterly. The information offers a glimpse at the expenses of a Harvard student and provides information about the larger community that supported student life. The precise entries indicate the lifelong habits of Storer as a careful and methodical financial manager that would prove so valuable when he served as Harvard's treasurer more than thirty years later. Storer documents accounts with the steward, butler, sweeper, glazier, barber, and lists these individuals by name. The volume also includes notes on expenses for boarding, transportation, wood, and pocket expenses. While most entries do not list specific purchases, Storer provides details on the cost of a Harvard Commencement in 1747 (including the cost of a diploma, money to the President, hiring a house, a boat, a woman, and "2 Negroes"), and a specific accounting of the different food purchased for the event; Storer also lists expenses for an 1748 "supper for the graduates."