Enantioselective Addition of Remote Alkyl Radicals to Double Bonds by Photocatalytic Proton-Coupled Electron Transfer (PCET) Deconstruction of Unstrained Cycloalkanols
ring opening of unstrained cycloalkanols by a proton-coupled electrontransfer (PCET) process, to 2-acyl imidazoles previously coordinated to a rhodium-based chiral Lewis acid. High yields and enantioselectivites up to 99% are achieved in 1 h. Mechanistic investigations support the formation of the remote alkyl radical by a PCET process, and theoretical studies explain the observed stereochemistry
The pinacol rearrangement of cyclopentylcycloheptane-1,1'-diol
作者:R.D. Sands
DOI:10.1016/0040-4020(65)80024-2
日期:1965.1
When cyclopentylcycloheptane-1,1'-diol was heated with dilute acid, the major product was spiro [5.6] dodecan-1-one. The diene, 1-(1-cyclopentenyl)cycloheptene, was a minor product, and no spiro [4.7] dodecan-6-one was found.
Study of I-Strain Relief in the Intermediate When Forming Spiro Ketones from Unsymmetrical Cycloalkylidenecycloalkanes, Their Dibromides, and Their Pinacols
作者:Richard D. Sands
DOI:10.1021/jo00081a030
日期:1994.1
Three unsymmetrical intercyclic olefins, their dibromides, and their pinacols were prepared, each so the two carbons involved at the functional group were part of a different sized ring. The pinacols were reacted with 25% sulfuric acid and with boron trifluoride etherate, the dibromides with silver nitrate,and the olefins with mercuric acetate and with trifluoroperacetic acid. The predominant spiro ketone found in each product mixture was used to determine which carbon, and hence which size ring, could better undergo the sp(3) to sp(2) or the sp(2) to sp(3) transition. The findings were consistent with Brown's observations on ring strain.
KAKIUCHI, KIYOMI;ITOGA, KAZUO;TSUGARU, TOSHINORI;HATO, YUKINORI;TOBE, YOS+, J. ORG. CHEM., 1984, 49, N 4, 659-665