A general approach to small [n]paracyclophanes

Cyanohydrins in Nature and the Laboratory: Biology, Preparations, and Synthetic Applications

“…Zinc iodide 11 or 18-crown-6 with potassium cyanide 12,13 are commonly used as catalysts for trialkylsilylcyanation: ytterbium tricyanide, 14 Lewis bases, 15 and other Lewis acids 16 have also been used. This method has been employed to prepare cyanohydrins of a wide variety of carbonyl compounds including sterically hindered ketones, 17,18 R,β-unsaturated compounds, 11,14,[19][20][21] easily enolizable ketones, and acid-sensitive ketones. 14 A fourth method of cyanohydrin preparation is transhydrocyanation from acetone cyanohydrin to the carbonyl compound.…”

In/Out Isomerism

“…Gassman and co-workers prepared a series of derivatives of in,out -bicyclo[ n .2.2]alkanes ( n = 5−8) through Diels−Alder reactions of cis,trans -1,3-cycloalkadienes. ,,− Few molecular mechanics calculations on these systems have been reported, and the in,out -isomers may be thermodynamically preferred for the larger systems, but it is plain that the in,out -isomers with n = 5 or 6 are severely strained. This is shown by some extremely large C−C−C angles in these compounds.…”

Selected synthetic strategies to cyclophanes

“…In 1980, Gassman and co-workers [ 194 ] have synthesized [8]paracyclophane via the DA reaction as a key step. In this connection, 1,3-cyclododecadiene ( 337 ) was reacted with maleic anhydride to give the DA product 338 (21%).…”