Nucleophilic addition to C,C double bonds. III. Chemical reactivity of 1endo, 4endo: 5exo, 8exo‐dimethano‐1,2,3,4,4a,5,8,8a‐octahydronaphthalen‐10syn‐ol and X‐ray structure analysis of its p‐nitrobenzoate

Abstract

SummaryThe title compound 1 is a further example of an olefinic alcohol that undergoes ether formation under basic conditions ( 4 3 ) although the double bond is not activated by an electron-attracting group. This unusual reactivity is due to steric compression, which is increased in the 10-methyl analogue 2. This forms the corresponding ether 7 at a much higher rate. -In a deuteriated medium, base-catalysed cyclization of 1 gives the exo-deuteriated ether 6, corresponding to trans-addition. -An X-ray structure analysis of 4, thep-nitrobenzoate of 1, is presented.Very recently we reported about the ability of several olefinic alcohols of the general type a to undergo ether formation to b under basic conditions [2] (see Scheme I ) . This uncommon reactivity is mainly due to high steric compression, which is more pronounced in compounds with R ' = CH instead of H.

Bicyclo[2.2.1]hept-7-ylp-bromobenzoate

“…For calculated and experimental norbornane and related structures, see: Allinger et al (1989); Pfund et al (1980). For related polycyclic p-bromobenzoate structures, see: Lloyd & Arif (2012); Lloyd et al (1995Lloyd et al ( , 2000.…”

“…(2012) (Watson et al, 1992). The Cambridge Crystallographic Database contains only five 7-norbornyl benzoate structures, but these are complicated by additional substituents and their associated steric interactions (for example, see Pfund et al, 1980). An ORTEP-3 drawing (Farrugia, 2012) of title compound structure 1 is shown in Fig.…”

The observation of remarkable effects of remotely connected but spatially proximate hydroxy-groups on the rates and regiochemistry of the birch reduction of aromatic rings and double bonds

“…x bonding conformation, has little effect on this distortion. For (30), (31), and the anion-radical of norbornene, the endoisomer of each is preferred over the exo-isomer by 24.5, 14.6, and 18.3 2 5 kJ mol-', respectively.…”

“…(30) and exo- (31). The origin of the pyramidalization of alkenes 3 7 and their anion-radicals 2 5 * 3 8 has been discussed elsewhere.…”

“…* As in the case of the norbornene anion radical,25 (30) and (31) each are predicted to have two stable geometries distinguished by the direction of bending of the olefinic C-H bonds, either endo, uiz. endo-(30) and endo- (31), or exo, uiz. exo-*The actual conformation of (13) is most likely that in which the hydroxymethyl groups are rotated so that the hydroxy-groups are directed away from the endo-cavity of the ring.…”