Rearrangements in the adamantane series

Conformational Studies on Oligosubstituted Adamantane Derivatives – Structural Features of Tetravinyl‐, Tetracyclopropyl‐, and Tetraisopropyladamantane

“…1,3-Diisopropyl-(4), 1-tert-butyl-3-isopropyl-(5), 1,3,5-triisopropyl-(6), and 1-tert-butyl-3,5-diisopropyladamantane (7) were obtained from the same synthetic precursor -methyl 3-isopropyladamantane-1-carboxylate (10) [10] -applying a standard set of repetitive procedures in 65, 77, 24 and 34 % overall yield, respectively (Scheme 1). [11] The typical synthetic sequence starts with the transformation of the methoxycarbonyl group into a hydroxyisopropyl group with an excess of methyllithium to yield the tertiary alcohols 11 or 14.…”

“…These were then converted into hydrocarbons 4, 6 or 5, 7 applying the ionic hydrogenation procedure [12] or Adcock's protocol, [13] respectively. The acid 13 was prepared from the alcohol 11 using a Koch-Haaf carboxylation, [10,14] and then transformed into its methyl ester 12 by treatment with diazomethane.…”

“…The fact that the corresponding 1 J C,C values in tetracyclopropyladamantane (8) and tetracyclopropylmethane (1) are virtually identical (Figure 3), then indicates that the ef-fects of steric repulsion between the smaller cyclopropyl groups and the cores in 8 and 1 are not very different. [9] methyl 3-isopropyladamantane-1-carboxylate (10) [10] and 1,3,5,7-tetrakis(hydroxymethyl)adamantane (15) [18] were prepared according to known procedures. Diethyl ether and THF were dried by distillation from sodium benzophenone ketyl, DMSO from calcium hydride, CH 2 Cl 2 from P 2 O 5 .…”

Reactions of adamantanes in electrophilic media

“…Judging from the ratio of the rate constants for solvolysis of 2-(1-adamantyl)-2-bromopropane (58) and 1-bromo-3-isopropyladamantane (10 4 : 1), an assumption was made 112 that the rates of bromination of the side chain and nucleus in 1-isopropyladamantane (59) should also differ by four orders of magnitude. However, since only the nucleus of 1-isopropyladamantane is brominated in the reaction, a complex reaction scheme including several rearrangements of carbenium ions was proposed to account for this contradiction.…”

New Compounds: Convenient Selective Esterification of Aromatic Carboxylic Acids Bearing Other Reactive Groups Using a Boron Trifluoride Etherate—Alcohol Reagent

“…The present investigation, along with those conducted earlier (2, 3, 5) clearly indicates that the boron trifluoride etherate-alcohol reagent is unique in that it is both mild and effective and it does not suffer. from a lack of generality as do other methods (6). It satisfactorily meets the esterification requirements of more classes of carboxylic acids than does any other single reagent known.…”